Repair Briefs - Test Gear, Industrial and Boating gear, Computer, Domestic and miscellany.
The following are repair briefs for various
equipment.The infomation is directed
to technically competant repair engineers.Generic terms have
been used to make this info less model specific,eg terms like
replace transistor Q123 have not been used.
The equipment is Test Gear, Industrial and Boating gear, Domestic and miscellany , computer.
I would be interested in finding
any other repair listings on the internet structured as i have
done ie intended to be less model specific. For convenience using search-engines,
use keyword divdevrep to target these files.
There is no point in contacting me about any of the following, the
repair job may have been done 15 years ago .
I cannot clarify or enlarge on any of the following.
Should the location of this file change please use the keyword "divdev7" in
a search engine to find it again
Test Gear
Converting Avo Model 7 to accept Avo Model 8 probe leads.
ie convert hook connectors to 4mm pins
Unscrew the screw terminals. Find length of 2BA
brass stud or length of brass screw and the central
brass piece of a 4mm chassis socket. Grind part of the
2BA thread so 4mm barrel section will fit on, Then
high heat (hot air gun perhaps) solder the 2
bits together. Screw in to Avo and push a couple of
grommets onto the exposed 4mm socket parts.
Avo CT160 valve tester
Needle sticking. It is surprisingly easy to remove the
meter on these once removed the 4 base bolts and
opened up and propped up in the lid.
Slackening the 2 bolts and studs and nuts that
act as fixings and terminals. If you overtighten
these fixings it is enough to distort the meter housing
and disturb the delicate movement.
To reset the relay manually just flip it
back once inside, clean the contacts
at the same time. The mains primary is about
46 ohms through these contacts for UK 240V.
The 210V/200V bulb should illuminate
if this relay is activated but someone had
disconnected this one.
Maybe of use to someone this meter
movement showed 50% with 14.76 volt
dropped through a 920K resistor ( for
checking meter movement without main
voltage over the place).
If the meter cannot be set
exactly on the tilde setting/ mains voltage
heater continuity especially if changing the
EB91/D77/CV140/6AL5 rectifiers, reset the
large preset on the rectifier board
between 2.34K resistor and rectifier.
Avo Valve Tester , the first one about 1936
Just the main meter section , no switchbank and valve base
section. Someone wanted for use rather than original condition.
Made up an outlet plug from some QM socket pins used
in reverse as the right diameter, using the siolder bucket end
as connector and soldering to the other end.
But unknown condition checked out cold as best
as possible. Only one active device
in this unit a Copper oxide rectifier
http://home.graffiti.net/diverse:graffiti.net/CuO_rec.jpg
steel bolt mount is horizontal.
Not for anode supply but for signal to the meter
(only 6 discs so limited to 6x 6V reverse voltage.
Slow variac powering up and not much happening
other than coming on (even that iffy due to the buried
switch contact uner the first transformer, for continuity
probes when connected through the top pannel).
If the mA/V control was placed in 1/3 of the scale
then needle went heavily negative.
Broken join in the 2 decade log , wire-wound, pot
track. Removed from circuit measured 14.4R on heavy
gauge wire and 90R overall. Break at the doubly weak
point where there is disjuncture between the 2 gauges
and also the log law change of depth taper is a jump
there. Easy to undo, remove , rejoin 1 turn less ,
down tight , lacquer in and later grind down to remove
any jump in height.
Back in working order but C/H leakage was a factor
of 3 over s, simulating by adding Rs to known good valve.
May not be correct , and no obvious index mark for the
outlet socket but going clockwise, viewed externally, from the centre pin of the
narrow spaced pins.
Heater (low?) , heater, D1, D2, A2, A1, G, Screen, K
At 95 percent mains (with broken mA/V pot) and 80, Normal,
10, 75 Screen, 6 heater, mid set zero ac voltages on these outlet pins
5.9,15.2,15,15.7,96,6.9,67, 5.9 relative to the "index" pin
Some R vales , black rod with purple band 74.7R
barrel Rs 115K, 1.5K, 400K to neon
Meterread 31R on dvm with 16.2mV on tips and
5.8 on the meter scale
With repaired unit unpowered and settings of anode 150V, S 100V
heater 6V, normal, set zero at 1/2, set mA/V at 5
set mA/V pot across ends 31.6R
nearby W/W single 6.8R and nearby
double 8.6R , 1.2R
CuO measure 294R one way round and 699 the other
46R w/w next to the rectifier
set zero pots 11.8R, 238R
24.2R across meter
Instuction of use pages in the front of 1957 Avo valve data manual.
Start with Set Zero turned fully clockwise and mA/V
to full anticlocwise. Set mA/V scale with pointer at the figure
in the AVT data column , and use the 50 mark "mA/V" when testing diodes.
Some useful info from a G8MNY
http://theskywaves.demon.co.uk/technical/Testgear/Early_AVO_Valve_tester.pdf
Avometer Avo model 8 Mark 5
Low or absent reading on all scales plus on AC ranges high variability with frequency.
New owner so unknown abuses. The select/cut on calibration etched 18.4 ohm resitor in ohm x 1
range burnt out so replaced with mixture of wirewounds and low wattage. The 270 ohm
resistor in the 3V AC line was charred to over 1K. One of the Germanium pair
of rectifier diodes was o/c leading to the f susceptability.
Someone had hacked into the meter movement area (broken covering)
probably to sort out false tripping cut out. Something was wrong with the movement
100mV over the meter would give about 90 per cent fsd.
Whether loss of magnetism,deformed return spring don't know reason - the coil
was not obviosly overheated (shorted turns). Put a 18 turn preset in parallel
with the small internal dropper in series with the meter (mounted on reversing switch) to
bring up the movement to 100 percent.
Notes - the basic idea is the chain of "current" resistors adds up to 8000 ohm accurate to
the last figure,this in parallel with the 2677 ohm of the meter gives potential divider of 1/30
in the 3V range with the 58K resistor .
With the meter in damped setting (shorted meter) foreward and "reverse" over each
Ge rectifier was .95V and .29V on a DVM.
DC resistance of the AC divider inductances (transformer-like device) were
<0.2 ohm,0.7,40.5,873,1592 and ,<0.1 ohm.
Bruel & Kjaer 8306 accelerometer
Beyond repair, probably dropped and shattered most of the
piezo elements at the core.
Probably originally 8 off 5/16 by 3/64 inch anulus discs
in series along the stud.
Probably assembled by tightening up the internal cylinder
with one ground/polished face
that stud goes in one end and Allen bolt in the other.
To undo, undo black covering and remove the pcb. Then stop the block from rotating and
undo the allen bolt relative to that block and base with connectors
Tightened with loctite on stud thread to some predetermined
signal output, then heavy block put in place and allen bolt tightened and varnished in place.
Just the number 4289 ,distinctive shape, in plan view, like a ship with a
blunt end and a sharp end, 4.5x2x2mm, black body 3 in line gold plated legs,
3 of these trannies used probably 2N4289 plus an E102 FET .
Crotech 3036 scope
Maximum intensity only
9x200V zeners gone high leading
to EHT of -2000V instead of -1800V
leading to punch through of 2kV capacitor and
destruction of active components.
Replace all and uprate electrolytic across 100V zener
Crotech 3132 scope
R422, 1kohm in 180V ps was broken.
Farnell LFM2 Audio Generator
Short lived function after switch on
and change of multiplier.
Replace the x100k switch
Fluke 77
No function.
About 1/3 of pins on major ic had disconnected
due to a heavy object falling on the front face
of the DVM.
Fluke 77 dvm
Functioning but displaying about 1 percent of true values.
Large bodied 1K ohm fuseable resistor near I/P o/c.
Gould OS255 scope
Random false triggering, coincident with mains borne spikes.
Someone had removed the power cord earthing
to the case.Also backlash on mode selector
switch due to worn nylon pot shaft extender.-
partially fill the worn "socket" with hot melt
glue and push in a metal "D" section pot shaft
to remould extender.
Gould OS4000 DSO, 1981
NATO No. Z4/6625-99-647-3625
This scope needs the connections made to the 4001 output
section for the scope to work in normal mode.
To remove that section remove bottom cover and then the 4
slot-head long stud/bolts that anchor into 'C' 'clamps'.
Gould / Advance scope
Model not known , from memory probably Advance OS15 or OS 25
False triggering due to faulty ps electolytic leading to
mains hum on the power rail feeding the trigger section
GW GOS 543 40MHz scope
no display,low EHT
EHT diode pump circuit fashioned on GRP circuit board with the board edges
exposed to atmosphere bypassing the encapsulation and ABS housing,allowing
ingress of water vapour and condensation along the glass fibres to the
component leads in a high impedance circuit.Rebuilt on paxolin board
Hameg HM103 scope
Lack of flyback suppression
Replace the optoisolator
Hameg HM412-5 scope
No T/B and trace off screen to the right
CMOS 4011 failure
Heathkit IO 4541 scope 1977
No vertical trace.
Worn out pot on the v/div switch assembly.
Recondition as per tips file
ISO-TECH IDM91 DVM
Dithering values on display
Clean the selector switch tracks and wiper
with solvent and spray with switch cleaner.
Keithly 128 DMM.
Display showing erroneous segments and multiple decimal
points.
Clean off corrosion on the pcb pads that connect to the display
via the rubber / wire composite Zebra bridging strip.
Maplin 920R pocket DMM
Nothing despite good batteries.
Compressed foam on the battery cover, added a
patch of felt to pack out
Kikusui COS5041TM, 40 MHz scope, 1986
Absolutely nothing on the display, even in darkened room at switch off.
Something wrong with wiring/connectors to the CRT heater, the orange glow is
visible under the shielding now attended to and the scope is working.
PDA/EHT of 7.2 KV
EHT transformer cover easily removes.
TL081, 1R, D880 mica .14mm no grease, 3.3K 1/3W over B-E
EHT transformer secondary 20.5R
Heater continuity 5.7R and transformer when disconnected 1.2R.
I never know how much a 300 meg/313Kohm,30KV, 1000:1 divider meant for
20K/volt meters & 10V range , but following measured with DVM, would pull down EHT.
yellow (focus?) -1045 to -1182 on varying focus control
orange -1777 to -1765 on changing intensity control
red -1736 invariant
brown -1736 heater, invariant
ribbon feed 60 to 80V on changing Y shift
blue 40V, green (astig?) 70V
red 50V, brown 40 to 120V on changing X-shift
Jitter in Y sense, both traces equally, that gets worse on warming
until they disappear off the top.
Q313 , 2SC2704 had a Vbe in circuit of .85V
and by desoldering 1.1V . Replaced with 2SD669A, also
for anyone else, similar are 2SD668, 2SC2911 and 2SC2682.
Replaced sillypads on both with mica and grease.
As DC coupled it made the 2SA958 supply transistor have
a collector voltage of -58V and due to heat there , looks like
a problem there instead.
3884 supply measures 17.9, 11.9, 18.5
D880 -19.6,-11.9,-20.2
A958 -1.5,-30,-1 (1.3V from TO92 tranny in Y section)
C-E resistance in circuit 1.3K , W/W resistor 2.7K
Paralleling 120K to the 120K that feeds into 4558 input
alters the output, so OK (diode here is ordinary
signal one ). Should be about -5V o/p
4 Y drive transistors should be about 6.6V and 122V
Crackled paint of resistor next to U6 100R
Scale illumination lamps blown, unloaded supply, at maximum of pot control
is 19.5V to paired up bulbs. Anyone ever tried droppered blue or white LEDs
for such purposes. Would require a reflector on the LED axis to throw light
off radially. Otherwise it will probably have to be 24V bulbs going in
there.
Bridge rectifier DC 139V, -36 and -19V,20V
Illumination controls C1846
Mains secondaries 32V ac, 147V ac
EHT transformer driver D880 , no grease on the insulator.
Y push/pull sw , furthest switch
rotating one next in line
main wafer 2-3/2-4/2-5 repeated for 6 highest ranges
front wafer 4,3,3 connections
Horizontal fuzz of same amount whatever time / div , adjust
astigmatism pot along with focus.
Chop/alternat oscillator breakthrough disappears
on replacing casing
Its possible to recase this scope with panels on upside down.
Marconi TF2370 110MHz Spectrum analyser
Display and storage OK but no counter.
2 problems due to bad thru' board connections of one of these 1975 double-sided PCBs.
One through board link connected the 5V from the analogue section to the digital
section of board AG1 that had knocked out the first 74s112. Replaced but counter
only working in range 160 to 260 approx. Another thru' board break to the 7411 on the
same AG1 board. Resoldered all such thru' board points.
Megger BM6 insulation tester
no function, no inverter whine
One of the BC214 had gone C-E s/c should be
about 650 ohm C-E. On microswitch is 2 outer pins
close and 2 inner pins open in use. Solder
3 wires across solder points to simulate
rotary switch contacts in M position, 4th not needed.
Nasty power trannie 'insulator'
I've never in decades of repairing seen the like of this one.
Insted of mica or blue/grey silicone sheet insulator under a
2N3055 type trannie.,at first sight looks like zinc or
mu-metal a dull greyish metal.
Just one of the 16 such trannies was B-C short and it was
only this one that had been replaced 5 years or so previously by
someone who had used this 'insulator' so presumably to blame.
On inspection/scraping it is probably aluminium with a thin
hard anodised oxide top and bottom for electrical insulation.
The edges including the holes are bare metal so
just 0.5mm or 20thou/mil out of position and the B or E pin will touch
the metal edge of the through-hole . Also just the tiniest microscopic piece of swarf will
puncture the oxide to make contact that way.
It is professionally
cut and drilled/punched so not some misguided bodger.
I measured the "insulator" small holes.
diameter 2.45mm and the trannie pins diameter 1.05mm,sanding back
the oxide to metal the oxide layer each side and measuring
before and after ,Al thickness was 0.5mm ,the insulation layer
was only about 0.015mm or 0.6 thou / mil each side. Asking for trouble I
would have said . On more of a safety note apparently there is a variant
of the above anodised coating to aluminium. These are pink and a
beryllium oxide coating so no scraping or sanding of that type.
OK SA 20-30-230 24V soldering iron.
Weak mains switch , replace with SPST in a part blanked off
hole and a separate neon.
These basic single temp controlled irons can
be changed to variable by bringing out one
of the presets on the control board as a
pot on the front (not noted which one).
Philips PM3311 scope
Not able to change the
(time/div) time-base setting. The knob has no effect, the
contacts are clean inside.
Multiplexer ( 74257 ) in the time/div circuit
was defective (reported repair).
Philips PM5770 pulse generator
Output on 10V setting but not lower settings.
Inside the screened attenuator box a secondary switch
mechanism comes into action in the 10Volt position
but was failing to return on spring action on lower settings.
Same symptoms for someone's HP 8116A 50MHz Programmable
pulse/function generator but relay driver failure for
that one.
RS 480-100 Breadboard
Loss of 5V power rail - problem with
button bridge rectifier losing 2 rectifiers or internal
connection.
Scopex 14D10 scope
Low intensity and a rough sawtooth waveform at mains
frequency instead of (no signal) bright line trace.
There are two large electrolytics on the mains side of the SMPS,
only held to the pcb by their wire leads.One had been jarred loose,
so resolder and beef-up the mechanical fixing of cap to the pcb with hot-melt
glue.Also this pcb (with EHT supply) is only held by 3 stand-offs and
with environmental effects the pcb had curved so add extra stand-offs
between the board and the chassis.
Scopex 4D10 scope
No Y amp
Broken split inductor L101
Check drain-gate2 voltage on 2x fets if low replace one or both
Scopex 14D10 scope
Nasty noise from the ps and nothing else.
Using an isolation transformer and observing on a scope
there was low level oscillation of the smps and one burst of
oscillator per cycle of the mains.This smps is the type with
the oscillator on the mains side of the pulse transformer.
All active components seemed ok and no leaky caps.
Putting a dc supply across the oscillator and varying
the voltage the drive to the main trannie changed state
at about 20V.Disconnecting the pulse transformer and
testing with a megger (high v insulation tester) there
was no interwinding breakdown and the inductance of
the coils looked right (no shorted turns).Eventually found
the O/P was being loaded by a faulty opto-isolator that
gates the beam current.It was ohmic between I/P
and O/P so removed and cracked open with mole grips
(vice grip locking pliers).Looking at the transparent
bridge under a 30x microscope there were tiny circles of
mold or fungus that had grown and coalesced forming
a resistive bridge between I/P and O/P.
Scopex 4D10A scope
T/B jitter
Due to oscillation in T/B
Replace fet BF244 (TR503)
Scopex 4D10A scope, 1977
loss of channel A which meant of course loss
of trigger to channel B unless cross-linked inputs.
Trace locate returned both beams.
The dual FET E421 at the input was duff.
The S voltage of both FETs was about -6.7V
instead of about 2V on the good channel.
Replaced with a 2N5189 which brought back
the second trace but very low gain., the
FET (S) dc was still -0.6V, changing the
bias by changing -20V supply droppers
2x 6.8K to 2x 36K brought the V up to 0.5V
and useable operation, up to 1MHz anyway.
Scopex 4S6 oscilloscope
Trace is only a diffuse glow
The 3K9 resistor connecting 200V rail
to the CRT astigmatism preset was O/C
from long term overheating so uprated to 1W.
Seaward PAC500 PAT Tester
False negative indication
Replace the CMOS 4000 series SMT device
see hints/tips for desoldering SMT devices.
Tektronix 5110 scope
Jitter in vertical sense of both traces.
Jitter present with Y plug in present and pressing
the beam finder and absent without the y plug-in
pressing the beam finder.
Poor connection in socket J604 of the small
auxilliary board behind the pcb with the sockets
for the plug-in modules.
Tektronix 7603 scope.
No display.
On the low voltage regulator board there are a number of
ribbon leads including 3 8way with no identifying sockets,2 8 way
and 1 10way.Someone had positioned the 8 way onto pins 3 to 10 of
the 10 way and put 130V on the 50V rails.Numerous individual
failures associated with the 50V and 50V sense line including the
transistor array satisfactorily replaced for proving purposes with
a 3046 array.Unfortunately one of the transistors in the U450
Tektronix hybrid (3 push-pull amp stages in a can) was kaput so
no Y trace movement and defocused spot.
Tektronix 7834 Storage scope
No power supply
The HV inverter transformer had shorted turns,a matter of rewinding another
as quote for replacement was 760UKP.
Telequipment D32 'scope
No fuction due to one of the 2 BDX36 transistors in the ps oscillator ,replaced with a
BDX35. Also 2 of the 6 Nicads were shorted (dendrited) needed replacing.
No intensity control due to ohmic 130V Zener. No Y deflection of either
beam below centre line of the display; no negative going traces. One of the collector
resistors to one of the Y-plate drive transistors was O/C ;replaced with double the wattage
and similar replacement for the matching dropper.
Telequipment S51B valve 'scope, 1974
Central spot only , no movement.
Main DC line at 480V instead of 380V.
I don't know if as original but the large 500 ohm
and 1K dropper resistors in the main DC lines were
mounted underneath and the 1K one had at some point
scraped the outer cover of the m/c both need mounting
on the other side of the board.
Replacing the DC fuse and removing the 1K resistor but
including the 500ohm then spot became a larger square
and X-shift movement but no T/B or Y-shift/deflection
other than the fixed square splurge. Replaced 1K and
slowly powered up via Variac in case of problem with large C4 electrolytic.
No problems and full function so maybe the 500 ohm shorting to case and
blowing fuse and not knocking out the mains transformer
winding - someone had looked before me so may have replaced
a blown mains fuse.
Telequipment 61a scope
No trigger
Check integrity of connection between
PC226 daughter board and motherboard,
and set R74
Telequipment D63 scope.
3 faults
1 High voltage discharge crackling noise. Even in the dark it was not possible
to see where the discharge was so probably in the step-up transformer or the
quintupler. The display was too bright and
post deflection accelerator voltage was too high so much reduced trace size
in X and Y sense.The CRT 2cnd electrode should have been
-1400V but was -2200V so EHT probably 19KV rather than 12KV. The EHT oscillator
transistor had been replaced by a BD131. Changing the biasing pot to the preliminary
drive transistor made no effect. The primary of the oscillator o/p transformer
was 56V pk-pk not the correct 38V. Although the DC voltage varied from 60V to
100V altering this pot. One of the DC divider chain of 3x 5.1M was o/c so no -ve
feedback component to the oscillator.
2 Traces in X sense squashed up to left of screen. One of the SPS5286 final
X plate drivers was o/c replaced with BF338.
3 The third trace (Right hand PI) was static bright line with no Y displacement.
A trace to 330 ohm,1.5W dropper from 105V to one of the Y2 driver transistors was loose
and touching another trace. With this 330 removed and no 105V then no 3rd trace, only
appearing on beam finding activation.
Telequipment D66 scope
No timebase
Y deflection and X deflection function but no timebase.The high
ohmic resistors biasing the timebase oscillator FET had gone high.
The drain of the FET needs to be about 2.5V before oscillation starts.
Telequipment D75 and Telequipment D83 scopes as far as p.s. and CRT drive circuits and faults
are almost identical.
Telequipment D83 scope
Variable and fading image similar to changing
grid cut-off pot R315
Failure of D304 6KV,10mA diode
Telequipment D83
Inability to focus
R323 gone high ohms
Telequipment D83
After 1 hour loss of image
Associated with switch (trigger-auto sw.)
on T/B plug in
Telequipment D1011 scope 1981
No ch1 trace and no trigger.
Initially checked the 8 pin DIL dual FET packages.
In manual as SU2603M but on board were Teledyne 1125-00 (8006 datecode?)
pinning 1-8 S,D,NC,G,S,D,NC,G so 180 degree replacable.
In circuit DC .1,5.2,.1,0,.1,5.2,0,0
I could not find data for SU2603M or 1125-00 so for anyone
trying to find replacement I tried 2 2N3819 bent legs to match
pinning - no trace and the S voltages rose to 1.7V and 2.1V .
Both problems due to physically broken front panel lever switch.
Neat design so choosing 1 of 2 positions of the dedent spring
can select 2 ,3 or 4 way. Choice of phosphor bronze contacts can be
1pole or 2 ,3 or 4 pole . The phosphor bronze bridging contacts
are only held to the core by 2 plastic nibs that had broken.
Each nib only 2mm diameter so failed as aging plastic.
Reformed
bent contacts ,used broken nibs for alignment and well glued in place
with hot-melt string. The detent spring is positioned around the small
nib for 4 way operation and up against the nib for 3 way (ch2) operation.
3 of the four front switches were broken so rebuilt and reinforced
remaining contacts including the fourth OK switch. One of the contacts
was broken and irretrievably bent so fashioned a replacement from
a phosphor bronze leaf of a lever switch but part from a relay
would also suit cut ,formed and glued in.
Variac V5H
Could not remove brush housing.
Presumably should be simple push against spring, turn and
pull but aluminium corrosion didn't allow any such movement.
Matter of hacksawing/ dremmel thin disk cutting a slot in the
aluminium arm down to the brush housing to give enough slack.
Weller magnastat soldering irons
Open circuit iron after being dropped or knocked.
It is usually the magnastat switch that is faulty not an o/c element.
These switches are very frail and it does not take much to knock them out of alignment
or even break apart. Take apart ,realign the contacts and reassemble.
Industrial and Boating
Advenda AD1 photographic enlarger timer.
Failure of relay to always pull off after timed interval.
A stock fault apparently-company advice to bang front panel with
a metal object over area housing the relay after yet another spoilt print.
Although 24Volt relay due to
unregulated supply the relay on voltage down to 15V.My replacement
24V relay failed to cut in unless whole unit was upside down.Replaced with a
12Volt and small dropper R in series.
Avenda AD1 photographic projector timer
Intermittant erroneous timing say set for 20 secs ,start down count and sometimes
would reset itself to above 20 seconds still counting down giving say 30 seconds count.
The circuitry is driven from a dropper straight from the mains. Simulated dirty mains
was the only way to cause this count problem. Found space for a small 12V
transformer and bridge rectifier to take the logic isolated from the mains except for
the timing input 1M dropper. Still don't like the way this feeds straight into
the clock input of the 50Hz divider IC.
Advena AD1 photographic enlarger timer
No display or function other than fan is active.
DC is derived direct from the mains and was only about 2 volts.
Powering up from a 15V bench power supply there was too
much current drawn for CMOS circuitry with the relay
coil disconnected. The 4025 was loading down the DC rail.
Boxford BUD lathe.
Failure of contactor latching on.
2 sets of microswitches , any of which will lock out on failure/ misposition..
Single one on fron door. Set of seriesed 3 ,
side door for gearbox, headstock end of bed for saddle endstop and
one in the headstock for A/B gear ratio select lock down (activated
by retaining hex bolt). Rear 3 junction box
is under the rear cover of the headstock.
BT DF100 Fax machine
Dead machine.
The external 24V ps was ok.
Disconnected main board and powered up outside chassis.
No 5V on the 74HCT chippery.
The Vcc pin on the UC3845N SMPS supervisor was only 8V ,
should be over 12V,cutting trace to this pin and trace rose to 19V.
Replaced the 3845,normally Vcc of about 14V.
Canon FC 220
Vertical blank stripe in image.
Toner running low and so allowing the developer (iron filings) to become
insufficiently diluted with toner leaving a gap around the magnet cylinder.
Broke open the toner/OPC/developer cartridge to redistribute the filings
as beyond just turning the cartridge over a few times. Used a mixture of
toner intended for Mita 512Z and Toshiba BD5120 but left a feint grey
background to the image. To break open the cartridge. The toner hopper
is under the embossed instructions so lay this downmost ,OPC upmost. Release
the 4 plastic catches along the width and 2 each side in different positions .
The OPC section will then comme away from the rest. Hold back the OPC shutter
flap and scoop the toner topup into the exposed slot. AE means Auto Exposure.
Car alternator (Ducellier but probably general) repairs
Firstly to test alternator out of vehicle and
on the workbench.Feed a low current less than 1 amp
into the exciter coil (the current path that
goes to the instrument panel lamp display,
this lamp is functional as well as for display ).On spinning
the pulley by hand with this current on there should be
substantial resistance to rotation and some
output volts.Most common failure on this test
is worn brushes
For s/c failure of one of the 6 3phase rectifier diodes
leading to no o/p. You cannot prove this sort of failure but occured coincidentally
when the car was in for welding . I suspect using arc welder or TIG /MIG on
a car can inject spurious currents in the body and blow even these high current
diodes. Makes you wonder about expensive CD players etc could be knocked out
in similar fashion.
I could not find replacement 50 amp barrel
diodes small enough to replace but
a TO-220 type packaged epitaxial double
rectifier from a switch mode power supply paralled up
fitted the bill
Another failure mode was failure of the regulator
giving some but insufficient o/p.Fairly
straightforward discrete circuitry inside the
soft sealed package.Actual culprit was an o/c .3W
6.2 volt zener so replaced with a 1W and resealed.
Claude Lyons TS2 mains voltage stabilizer.
Output following input rather than maintaining at 240V ac.
Problem with the 20mm fuse-holder with the 500mA fuse
supplying the servo-controller.
Courtenay Solaflash 2 photo studio flash unit, 1982
Xenon lamp tube
8cm major and 1 cm minor diameter , only markings 3X on positive end and 2J on
the other end.
Fails to flash.
Worked out how to discharge the caps and then remove the innards.
Remove 2 screws near the IEC inlet and 3 other periphery screws
to release end
cap. Discharge the caps via insulated probes and at least 100 ohm/10W
resistor before taking further apart.
Remove 2 screws on front reflector around
the edison screw socket and disconnect the wires to the tube.
Remove one screw near the handle and 4 around the slide out section
and slightly turn to slide out the rear.
1982 with components left over from the 1960s, those, don't even know the
generic term, flange stand-off flesh-tone background rod resistors.
At this stage probably problem with the 400V , 2A 2P4M SCR.
Nothing much else active, MPSA56, 2x 1N5407, 2x 1N4006 , BZX61C68 1.3W
zener.
The caps hold probably charge for hours after disconnecting from mains.
Putting a neon bulb and dropper over the trigger transformer gave plenty of
strike even in room lighting.
I've an old reserve piezo gas lighter that the metal grounding barrel on the
end falls off, ideal for testing this tube, but no flash over.
With 2 compact camera xenon tubes in series and a 1K, 10W dropper and the 2
camera trigger surfaces connected together to the existing trigger circuit,
it will reliably trigger the tubes to rather unstable continuous light ,
until I switch off , as 10W is not enough for continuous dropping.
I once triggered with the piezo gaslighter, proper trigger disconnected, but
didn't work the next few times.
The owner reported it would intermittently not work before giving up totally
, so I assumed it could not be a tube problem , well not gasifying anyway.
I've now tried 2 xenon beacon tubes in series and it works every time on
full or reduced settings. For continuous high rate of fioring
it would need 4 such beacon lamp tubes
Also works every time with the piezo gaslighter
when its ground plate is connected to the flash unit ground
Now I've separated the tube from the reflector enough to clean the tube in
the area where it descends through the reflector
http://www.diversed.fsnet.co.uk/xenon_tube.jpg
I can now see all is not well.
The cloudiness in the cathode end of the tube (only) is on the inside and
there is a patch of distinct blackening marked with a yellow line.
General black background is conductive foam for picture contrast , the
yellow wire is the trigger wire connected to the loops around the tube, no
silvering. The gaps 2 turns up of the spiral wrap at both anode and cathode,
would they be breaks or like that at manufacture?
It is after all 25 years of commercial photo studio use.
The slave action via LDR also checks out
Powering up, switching off, and triggering with piezo and measuring before
and after V then 42 joules per discharge per beacon tube. It may be
advantageous to wire in a pair more of these beacon tubes to make 4 , to
spread the load, at 2.50 GBP each compared to 70GBP for a not exact size and
fit single tube replacement.
Neon extinguishes or flashes when cap V is low.
With the 5407 board removed it is possible to work
on the trigger cct etc without having the 660V on the caps.
330V plus 330V. 2P4M replaced with TIC126N
1R5 big dropper in series with 660V and discharge current
flips the reed relay which in turn trips the 48V
relay (5.6K in cct)for recharge lockout.
Full/reduced power shorts the 100R and 1.5R
Globe lamp 150W, 240V
Also 44R dropper.
LDR feeds the base of the MPSA for secondary slave
action from primary flash lamp.
Mains transformer in cct 980R 117H, 500R 52H secondary
163V ac in use
Demolux D6070 overhead projector
Intermittent light o/p.
Replace the thermal switch on the lamp reflector
assembly.
Diamond force by Diamond Guard Corp. ,diamond checker
Complete non- operation .
The rear panel has to be broken free from the front and middle
section to gain access.
All 3 NiCads dendrited (short circuit) also poor physical
integrity of the spot-welded tags on these cells
Digisonic 502 ultrasonic metal thickness meter
Display only shows 1 in all modes.
1978/1979 meter using double ADC ICs ICL7103A
and ICL8052 4 1/2 digit converters.Luckily
these were OK,the 74C00 on the display board had
one NAND gate o/p stuck high,replaced with a 74HCT00 ok
The conformal coating may have been breaking down and causing an
oil film on the board which could have seeped into the IC
Electric fence "Electric Shepherd" ESB 250, 1986
no output
Input side measures 5Mohm, HV output side 12.7R, but looks like a standard
mains transformer.
As I cannot see how the high current side of a mains transformer could fail
I drilled out the rivets.
If originally a mains transformer, looks like one , it had primary 0.4mm
wire and secondary 0.9mm wire. 0.9mm wire has failed .
Fence output voltage o/c 8KV on the label. 9 seriesed 0.22 nF P/D Z3200(no V
stated) across the output and also 47K, 1W dropper to 2 seriously blackened
defunct neons in series.
Well I would not have believed it unless personally witnessed.
As the o/c must be on the outer layer of the transformer, I stripped off the
cloth tape. There is indication that damp air has got in this unit but not
flooding or internal drips. But in the middle of this outer layer, with no
sign of corrosion or damp under the tape , generally, there is one spot of
blue green corrossion and a small break in the 0.9mm wire.
Maybe a spot of acidic something at that point on assembly and then years of
damp air. Bridging the break gives resistance of the winding of about 0.2
ohm.
Powering on a variac, could not take higher than 150V (saturating) so
assuming it is 110V , 50W transformer ( or problem on the original pimary ) output
read 4.7V ac , no load, for 110V ac input.
Back working with proper bridged repair, new neons etc , at least it fires a neon via 100M ,
(0.1G ) dropper. The casing screws mayvbe
UNC which may indicate USA but label has UK address. Electric Shepherd
printed on the PCBs.
1000:1 EHT divider to scope showed about 1.5V pulses which presumably is
consistent with no load 8KV. Left the bank of Cs and neons in circuit ,
giving about 1.5Kv peak pulse. Nice strong blue spark with a spark plug
(not known gap as lost feeler gauges)
Of course the 110V primary is now used as the secondary here, for the
voltage step-up. Internal construction looked the same as mains
transformer.
0.1R, 3R3, SGS 50 679 9 501 (TO220)
47K 1W, 20uF 400V, 4584 S2512NH
Elu MOF 96/10 router.
Excessive arcing on the armature.
First problem the owner had inspected the brushes and had broken
the pcb holding the interference suppression components. Bad design
with small neck in part of board that seats in the casing . Needed
hardwire soldering and reinforcing the board.
The main problem was a short on one of the stators. Now how
to disassemble the housing. Drift out the roll pin through the large
diameter slideway pillar then the base will rotate around the small
pillar to access the 4 screws under the motor. Mark and unplug the
wires going to the stator,mark and remove the brushes. Remove housing
and then circlip retaining small slideway pillar to remove the base.
2 long screws retain the stator housing.
On one of the 2 stators the exit wire crosses the first turn of the entry wire
where there is maximum voltage across the enamelling and with vibration
etc had broken through shorting out all that stator (bad design again).
Forced apart and introduced some thin insulation material and varnished
in place. Did same on the other stator pre-emptive.Reseated brushes
with armature seating stone gradually raising drive voltage via
a variac supply.
Measured Inductance,resistance for this 220V,3.6 A motor.
Each stator 6.1mH,3.5 ohm. Armature 28 section .75 ohm per
section and 5.8 ohm across diameter that is across 14//14 sections.
ETA Tool Co, Leicester coil winding machine approx 1920s, later than 1912 anyway.
( An internet reference gave info about wording form on brass
name plate on ETA lathes relating to the age, on this m/c the plate is
just to left of the 7 digit turns counter in top pic below )
This machine had been in a garden shed for years and was
seized up with surface rust, but brushing and lubricating
brought the leadscrews, traverse reversal clutch etc into operation.
The contiuously variable gearing between turns and traverse is
2 plates, one driving and the other driven, with a lead screw
positioned jockey wheel connecting the two. The tyre on this
jockey was totally perished. Standard 'O' rings are too small
minor diameter. But filling the periphery with 2 small O rings and
a rectangular section VCR pulley tyre was the nearest I could get.
A rubber suspension band for car silencer suspension would stretch
and fit to this pulley but would require cutting back the cast-iron
frame to give space. Decided to use VCR tyre and pack out the gap by
gluing a platter from a 5 1/4 inch hard drive to the driven plate.
Ground down the edge a bit as a bit over size, also the thou per turn pointer
holder needed cutting back. Paked out the 4 prong spring plate
with 4 thick washers. Machine lacked the supply spool
holder back tension arm. Made a pefectly satisfactory
spool holder by mounting on a couple of ball races and spool
mounted vertically. Then removing the felt slip clutch section
from a VCR, mounted touching the spool and other part
tied back to the support arm and different weights on top of
slip clutch. Calibrate with different weights and monitor tension with a lever arm
load guage. As low 1 oz back tension is possible with this method.
To even out the wire flow for heavier gauge wire, pass over a pulley
pivoted on a swing arm, pulled back by a light spring, position
or change spring strength to match back tension.
The traverse scales on this old machine are 2 to 15 thou per turn
and with the other 3:1 gearing and spindle 6 to 45 thou per turn
not SWG as I first thought. Opposite sense to SWG , high SWG number
is low thou per turn. Ruler in pictures is cm and 5mm markings.
If the wire supply kicks back( better than forward and breaking
fine wire). Check the anchor bearings at the end of the
traverse leadscrews. Take up any slack that allows the screw
and so follower to move axially on the reversing cam kick.
Too much will give too much back torque to the variable
gear drive system. For very fine wire I use a small PTFE
thru chassis terminal with wire going thru were
the pin was. ptfe squashed and
then mounted on variable/settable metalwork
for the correct angle. closeness to former.
With as straight as run as possible between
mandrel , PTFE and supply spool. To give some slack in the wire,
to allow for snatching/uneven slip clutch by allowing the supply wire to stretch
I mount the supply spool vertically about 16 feet away with
slip clutch and adjustable anchored weight on top and then a felt clutch
about 2 foot from the spool, far enough for up and down
motion along the spool. Felt clutch made from a strip of
felt wrapped a few turns around the wire and then held
in the clothes line notch of a sprung clothes peg , fixed
to a support.
From Avo/Douglas coilwinder data, going on the lax side of the spread ,
for the excess amount of traverse over the width of wire
or the winding will upset and overwind without it.
Because of dirt, non-linearity, inaccuracy of drawing die,
enamel thickness, irregulatity inback tension etc.
50 swg 20 percent
46 swg 8%
38 swg 6.5 %
30 swg 5%
25 swg , 4%
UTS for 40 swg copper wire about 300gm, I measured UTS of some measured 0.09mm
(classed 45 swg or 0.071mm so assume measured gauges in the above table)
diameter wire about 120gm (by placing a weight, wrapped in some soft felt, on some
kitchen scales and then lifting up with a loop
around the weight and soft anchored around a finger and half
decrease in scale reading . So set back tension at about 1/5 of UTS
for sub 0.1mm gauge. Thicker gauge data from
a powered coil winder machine maker for 0.2mm copper wire back tension of 300gm,
0.4mm 900gm, 0.6mm 1.8Kg, 0.8mm 3Kg, 0.91mm 4Kg
After a trial run or two it may be possible to decrease the traverse
rate a bit, less excess traverse.
Incidently I think the ETA reversing mechanism may be better than the
Douglas one, for fine wire anyway. I seem to remember that if everything was
not just perfect, then sometimes with the Douglas, there would be too much of
a kick on the traverse arm and so break the wire, at reversal. I discovered
that the kick I was getting on my ETA one (in the right sense of slackening
rather than stretching, in both directions of traverse) was just due to a
slack end bearing of the leadscrew. The ETA uses a rubber rimmed cam that
engages with a flywheel to flip a dogclutch across to engage cleanly
with the reverse set of cogs reversing the direction of the chosen
leadscrew. The Douglas reverser throws half nuts between leadscrews
so not as clean engagement.
A tip for coil winding fine wire. Grind/melt into the
core of the spool , if a large one, so you make
contact with the first layer and solder a small piece of wire to
it. Then you can check continuity , no wire breaks in
the coil , at any stage. I foregot to make a lead in
of intermediary thickness wire between the primary and HT wire
of a magneto and the wire broke at the solder point , due to
tension building up on the winding.
Genrad 1659 RLC tester (quadtech ) , various models 1990s
The advantage of these older bridges in a production
environment is the auto-ranging is much quicker than
the more modern ones.
I have the service manual with schema and repaired
a lot of these so a lot of info on paper for
power-up failure display codes of
555 5 .00xx
222 4
just a 0 , sometimes flashing 9 instead
dealt with but would have to be on a consultation
basis as a lot of paper records. The internal/
external voltage bias is confusing at first sight
giving wavering displays in certain settings,
but with no appled dc V, would
seem to be as designed. Resetting the SRAM
by lifting the IC , disconnecting its supply
is permissible if erroneous data gets in
there while still operating but a voltage spike
on the D.U.T has killed some of the electronics,
before blowing the "protection" fuse of course.
Otherwise problems associated with dirty keypad,
key bounce and poor 6 line indirect connection
to the keypad. Ground down the subboard standoffs a bit to give
deeper socket contact. Very feeble toggle action
switch that looks like a slider switch. Can be replaced
with an ultra-miniture DPDT toggle switch with a
bit of hacking/grinding back and repositioning of
the pcb terminal holes. The fans have poor
bearings but fan can be replaced with small 12V
pc smps fans driven off the "12V" supply cap rather than 110V.
All ICs are plated through soldering so tough
going removing duff ones but plenty of room for
turned pin sockets before replacing.
Added a "bund" of a large wide rubber belt
around the test slot, glued to the pcb,
to catch any stray wires as used in a production
environment. One of the nearest chips is a 40GBP
LH002C IC.
GSP Graphix 4B vinyl letter cutter
Failure to complete self test on power-up
This m/c is like a beefed up Y-t plotter with extra stepper and double belt and splined
shaft to turn the cutter knife to match the x-y angle of cut. One revolution of
the cutter matches one rev of the this stepper motor and the notch on its spindle
plate gives the initial
index position.Failed opto-coupler so failure to find index position.
IGG (going by my memory, years later) moving LED sign
I tried repairing one where damp air had got inside and corroded pins ,
mainly on the data line expander/multiplexer chip , inside the sign. So parts of letters
were missing. Removing the big chip , abraiding pins, and soldering to an
intermediary turned pn socket worked for a year or so and then corrosion got
down inside the encapsulation - could not find a direct pin for pin
replacement, but with some research a functional replacement could probably
have been found.
By expander I think it was something like expanding 8 data lines from the
serial receiver up to 96 lines for 80 columns and 16 rows or whatever the matrix
was, so sometimes column/s would be missing and sometimes row/s missing
Ilford Ilfospeed 2001 photographic processor
Smoke and crackle coming from terminal of fixer tank immersion heater.
Severe pitted electrolytic ? corrosion of stainless steel tank around the mount of
the immersion heater leading to small leak of solution including seeping
between live terminal and ground leading to chemical smoke.
Demounted heater and cleaned mounts and stainless steel
tank. Cut rubber washers and pad from lorry tyre inner tube.
One rubber washer between flange and inside of tank on
unaffected side. Other side cut 5/8 inch hole in a steel plate
large enough to extend beyond porosity of the st/st. Remounted with rubber
washer next to heater flange then st/st plate then large rubber pad then
inside of tank.
Interphase 20/20 depth sounder and speed log
Missing transducer connector
The owner's dog had chewed the end off the lead and the owner
had thrown the remnants of the plug and not the dog overboard.
Worked out which of the 7 leads went where.
Piezo black (RX) and blue (TX)
Hall effect Red(5V) green (O/P)
Brown and white 10K NTC thermistor for monitoring sea temperature.
Jobo CPA2 or D5270 Professional photographic processors.
7 of these m/c with similar faults due mainly to condensation /corrosive
chemical vapours mainly.
1 Erratic motor speed due to errant CMOS 4001
2 Catastrophic flooding in base of m/c.Replaced about 6 traces
on the base PCB.Replaced combined motor switch and pot with separate
standard pot and waterproof covered toggle switch as original
switch disintegrated.
3 Slow and erratic motor drive.Replaced relay driver BC337 with higher rating
Tr after checking back emf diode.Broken pot track so rplaced as in above example.
4 No motor drive due to defunct op-amp.Drive trannie and motor can be checked
by taking the base of the TOP66 trannie via 1K to rail voltage.
5 No motor drive-Replace the motor switch mechanism yet again with
standard toggle switch with waterproof cover through a convenient part
of the top cover.
6 Intermittand motor drive with RFI on nearby radio.The 20V transformer
primary had fault buried in the epoxy.Replaced with a 18V,25VA standard transformer
mounted diagonally.
7 No motor drive. Motor failure due to build up of brush graphite dust from
commutator wear and
excess lubricant getting into one of the brush housings and gumming up the
brush so it could not slide. To remove brushes bend back the 3 nibs on
the back plate. Before remounting wedge back the brushes and with fine
wire anchor back both the brushes then release when replaced in housing.
General note: to work on these machines disconnect one side of the heater.When
finally checking without a water bath,with capillary sensor touching the element
power up for short durations with the thermostat set to minimum and the thermostat
should cut out.
Kestrel MIG welder
Erratic speed of feed motor
Broken pot control , replaced 2.5K pot with
10K wire-wound in parallel with 3.3K .
CEM Electronics board
uses 7808,BU806,CNY17-3, LM311, LM324
MCP3021Z, GD4093
Kreonite CPE31 Photographic processor
Blown fuses F1 and F2.
The QM connector at the rear of the control pannel had corroded contacts that had
then overheated causing charring and adjascent pins arcing across.
A general note for photographic processing equipment:- Beware of the bleach solution leaking
on to electrical areas as it leaves a high conductivity film when evaporated
Kreonite CPE31 Photographic processor
Pumps and heater not working.
The line and neutral fuses to the pumps,drives and 240V to 12Volt transformer
were O/C. Nothing obviously wrong other than catastrophically
blown fuses. Replaced fuses and all ok while in attendance but another day
a repeat performance of blown fuse.
Suspected intermittant problem with a pump so put 1Amp
fuse and in-line holder in line with each pump. Again occured
but only one of these 1 Amp fuses blew. It was an intermittant
seizing bearing problem with one pump.
Another pump problem (Little Giant Pump) on a different Kreonite
machine was no fluid transfer because the multipole magnet had
become unglued from the impellar and was rotating on its own.
Cut 3 pieces of silicone sleeving arranged 120 degrees apart and pushed
the magnet onto the rest of the impellor. Trickled in runny epoxy to bind
in. No reported problem with chemicals in use breaking down the epoxy.
Another problem with the geared drive motor-no function. There is a Klixon
relay as a 3 tag contactor external to the Bodine Electric fractional motor
and gearbox. A small plastic plug nest to
one of the blade tags had dropped out allowing the blade to move and break
the wire to the coil.
Lokata CC/ADF Radio direction finder
Rotating ferrite rod housing - opening.
Don't unscrew the top metal piece. Undo 2 screws
to remove the farings and then the multiple nuts, bolts and plates.
Makita DC9100 Drill ni-cad charger.
Dead
The click switch pressed to initiate needed replacing.
Metz 45CT5 professional flash gun.
Stuck in one mode setting.
The plastic radial linkage under the top setting dial had disengaged.
Reconnect and beef up with hot melt glue.Unfortiunately I had disassembled
the compound switch and PCBs to get to it.This is not necessary as there
is enough clearance to reposition the lever now I know how it works.Reregistering
the position of these PCBs and switch elements is finnicky.
MTE UC 15? / U15 ?, 440 50 , 3 phase contactor for a 5 hp lathe, approx 40 years old
Open circuit coil.
Bobbin and cloth and wire 74.4g, Bobbin 12.9g
Core of bobbin 0.8 x 0.85 inches x 0.9 width
Outer 'diameters' coil with cloth wrap removed
across 'flats' 1.2 and 1.35 inch and across 'corners' 1.54 inches
Counting off gave 6,250 turns of 40 SWG, summed total because the
varnish presumably had part melted over time and coalesced so wire
often breaking on unwind.
Outer, approx half, about 96 turns per gram and innner section
about 113 turns per gram (see tips files for counting-off ).
Rewind of 6,250 turns gave 876 ohms, coil voltage 240V
30 gms of back tension was not really enough for
the coil bulk to seat well inside the spool end pieces.
A second coil rewind ( for the reversing contactor coil which had
failed previously ) using same wire and
40 gms of back tension gave a more compact coil
and 840 ohms.
Nasa Video Navtex (marine radio data terminal)
No display.
Black screen except at switch-off with a flare of green.5V
regulator OK.Disconnecting the ribbon cable to the digital
board and local mains interference from nearby fluourescent
light starter would induce hash on the screen.The two casing
fixing screws at the top of case were too long and had cut
two of the pcb traces.
OJ ELEKTRONIK Thermostat (Denmark)
Elektronisk, the screw terminals ,mains and signal
rely on one pin soldering so torque on screwing
can easily twist/ break solder joint
Olympus pearlcorder S909 dictaphone
Audio howl from the speaker on play,FF and REW.
Worn function switch ,cured in simillar manner to the m/c above.
No need to remove the PCB as the pins of this switch are exposed.
OPC problem on Toshiba A3 photocopier BD5120
Scratch lines on the OPC but of course prohibitive cost to
replace. A much older (by 15 years or so) sliding top Rex Rotary 7320
m/c otherwise worn out had a good OPC drum. Dimensions
of the drum were the same but the original central rod was 10mm
and Toshiba is 7mm so packed out with rolled up brass
shim to suit. One plain circular spiral and the other flatted to
engage with the drive pulley,both heated up and solder admitted
capillary fashion to make robust brass/solder packing pieces.
Rex rotary m/c is the same as Mita 152 as far as the
mechanicals are concerned.
Toner compatibility for the Toshiba BD5120 ieT80P
OK but neutral exposure setting may shift from centre
Mita 152 OK
LZR 1200 (Dataproducts USA toner) OK
Kodak Ektaprint K Toner ok but needs 50K ohm
or so beween toner sensor signal line and 0V to stop
the false toner replenishment motor on signal.
Canon ,unknown model,container 150x105x60mm with one corner cut away OK but grey rather than black
Agfa X35 no good ,grey background ,not white
Philips 390 Dictaphone.
No functions
2 possible faults as neither looked right and worked afterwards.
The internal /external switch on external dc input socket was iffy,the
owner only ever used batteries so bypassed this switch and blocked socket
semipermanently. The mode change switch under the speaker was loose.
To get open remove 4 screws and pull away the mode swich knob. To get to
the mode switch desolder the 2 speaker terminals.
Philips LFH 0510 desktop dictation machine
No tape functions
The owner assured me that he had been using the m/c and
the jammed tape.After taking the m/c apart it was obvious that
the tape head assembly is fixed to the deck so not a matter of
failing to retract.The owner had
tried to use a Sanyo cassette in a Philips machine,they are
not compatible.
Plastimo AT50 boat autohelm
Dead after rudder hitting rock.
The back stop of the lead-screw failed breaking free and
breaking the wires to the compass etc. Compass wires red to
the 7808 8V rail and black to negative. This volt. reg.
needed replacing as no o/p and the backstop anchor refashioned by
drilling 8 holes in the adjascent plastic and holding together with
4 cable ties plus gluing up. Replaced housing screws with small
O rings under the heads for water seal rather than plastic covers.
To dissassemble this unit remove the 4 screws holding the compass
to the body and disconnect the 3 wire connector. Remove end
clip and ring on lead screw cylinder so
the tube can pass totally through the housing. Release the 4
screws on the end cover where the power lead goes through and
remove all internals through that end.
Precision Grinding (PG Ltd ,Mitcham) Optidress E
Microscope and X,Y Tangential and Radial positioning for precision diamond grinding.
Long term problem loss of radial transducer reading but more immediately total loss of display
in all traverse senses.
Total loss due to break in the 8 wire 9 pin Amphenol M9P and M9s lead. The whole
system is initiated by turning the tangential transducer fed by this 8 way lead. It also
caries the signals to the radial transducer. These transducers are Moire fringe
structures. To test off machine connect 5V to positive of Tx and 180 ohm to low side
back to earth. This supplies the 2 IR Tx LEDs. The receive side seems to consist
of 2 phototransistors with 2 optical gratings 1 for mm the other for imperial and
for directional sensing. The grating is observable under a x30 inspection
microscope. These o/ps each need 20K or so to earth to bring
down the o/p voltage from 5V. Changes sinusoidally with position. Because the radial Td is
closest to the active grinding area
this 5 wire cable had been wrenched and a short circuit at the point of entry into the Td
housing which was broken also leading to ingress of grinding dust. Apart from a good clean out with meths and
replacing with beefed up cable and new end plate (cable end bent at right angles
and seperately anchored to the end plate, it worked again. Beefed up all theese
Amphenol plugs and sockets which were all broken in some way, with
cable-ties embedded in hot-melt glue. A couple of the locking skirts were
broken but same thread as some cut-down ,military connectors so used these.
Wire breakages due to bad cable anchoring in these plastic Amphenol connectors.
Removed the inadequate rubbery grommet/compression rings in all these connectors.
They do not really stop the cables pulling or rotating in the barrels.
Replaced with 3 small cable ties tightly pulled around the screened cable. One inside
the first cover,one between this cover and outer,hot melted in and another
on the outside again melted in with the end of nylon spiral-wrap cable wrapping
the length of the cable. Noted the ohmage to 0V of each of the 8 internal presets before
adjusting as per instruction manual. The wiring of the 2 separate 5 pin ("domino" rather than ring)
connectors is not mutually compatible
Protimeter dampmeter masonry prope, with sliding hammer action.
Don't use in an awkward position so the pins are other than
right angle to the surface or the high carbon steel pins will
shatter.
Making-do lower grade pins , presumably pucker ones have tungsten tips.
The proper pins are 2 inches long and stepped diameters of
0.08 and 0.098 inches. Start with 2 pop-rivets with highish
carbon pins of 0.09 inch diiameter. Remove the aluminium
caps and grind points on the other end. Push through
the plastic housings and place 2x2 washers in the innermost
recesses to localise the ends of the pins
Rexon SM2150 E, sliding saw, 2005
Intermittant failure and then permanent non-saw
action.
There is a ventillation path around the electronics
in the handle, totally clogging the internal
space plus the 3 switches with sawdust. Contacts had arced across
and burning the sawdust across the contacts.
Replaced the microswitch and reconditioned the
other two.
Uses triac BTA26-600B and controller IC marked
FEGO 153S 0439W BA49K1
2x 15K, 100, 25R, 5.6V zener plus
another unknown zener.
Some unpowered DVM resistance measurements at mains plug
laser on, 1.2M and 6.4M in reverse sense
1) 5M, main power sw 3.7M
2) 5M, " 6 ohm
then reversiing polarity
1) 1.2M , 1.1M
2) 1.2M, 6 ohm
Rexon SM2150 E, sliding saw, 2005
A heavy lump fell onto the control box, saw ran for a while
when next used
then packed up with a puff of smoke.
One of the ferrite rings pushed down and partially
broke solder contact which then overheated and
burnt up. Unwound a turn on the ferrite and burred
away burnt patch.
BTA26600(8)? / (B)? triac
62R measured across triac. Ferrite filter coil
between motor (L) and 5,000/3,000 switch common.
100R resistor to triac gate.
"laser" 1.5V diode test on 2 lead supply to the light
Heated and unstuck the label over the control box
and glued a sheet of aluminium on the outside covering
the crack and then label back over. To check out, initially,
disconnect the saw motor and replace with a 60 watt
lamp - glows half bright and flickery on 3,000 setting.
Rock-ola 451 , 1970s juke box
The main fault that I was asked to sort out was the owner realised that the
deck motor suspension grommets were perished.
He first tried removing the whole deck drive sub chassis but failed ,
reassembled and just removed the motor and replaced the grommets.
Unfortunately he had twisted something along the way , the mechanism
seriously jammed and he gave up on it for some years.
He (using levers) or the mechanism had managed to bend the the deck
chassis sublate so the extended angle plate/latch
from the disc-centre lifter was twisted. This latch then could fall and
catch at the end of the plate with the long slot so jamming things good and
proper. Also twisting the angle plate at the double cogs drive that connects
via long rod to the stylus brush arm etc.
To remove the deck sub-chassis plate remove the 2 bolts at the
transfer gearing housing the one nut on the stud through the deck
and the nut on the far end of the other stud, access from beneath.
Gain access to this area by disconnecting lamp plug and speaker
plug and lifting off the whole front panel.
Straightened things out and reassembled and that all works fine.
The chromed plate with the raised curved sloping section is positioned
so that the chamfered lower section of the bronzy speed change jockey
assembly moves over this chromed ridge, bit confusing if removed trying
to find a second stud nut holdig the deck sub-chassis..
Secondary problem
Failing to grip disc off the deck to replace in carousel.
The gripper was kicking up before the arm retracts inwards so was above the
disc rather than peripheral to disc before grabbing and lifting.
The m/c has not been used for some years and and the grease in the
paired cog area had gone sticky.
Holding the gripper arm down with a bit of finger pressure allows gripper to
work.
Also using service switch to step the drive the gripper arm repeatedly lifts
and then drifts back (when motor switched off) during the gripper contraction sequence
until the point at which the
full lift drive engages. Squirt of WD40 betweeen the cogs and mechanism cycling
cleared that problem.
I was looking at the manual and there are 2 ICs just marked as reference
numbers 45762.
These are pinning compatible with MC1437 or MC1537 it would seem, Motorola
of that era.
May even get away with MC1458 or MC1558.
Although not a problem with the amplifier electronics, just though I'd put
that info on the net as it does not seem to be out there, whether the actual
devices have original Motorola markings or not I don't know
as I didn't look in the amp housings.
Sanyo Sanfax 100 fax machine
Symptom copy functions ok but no telecoms
Replace reed relays
Sanyo TRC 8700A 'dictaphone', 1986
No play or record - broken belt.
Replaced both belts. Quite well made inside
2 motors. The 2 header connectors DC voltages in play mode
and 0 is approx 0.
0,32,25,13,0
0,0,0,5,0,0.7(average),0.4,0.4
Sealine MC5500 Marine VHF tranceiver
No receive audio
LFB12 ceramic resonator gone resistive due to
Silver migration round edge of one (thinnest) of the
4 internal resonators. For silver migration , research
the term "silver mica disease"
Seavoice RT100 marine tranceiver
No function Rx or Tx.
This 12V unit had been run on 24V for some time.
Replace 2 1N4002 diodes near the relay,2 trimmers in
the Tx section were duff,one s/c the other broken.
On Rx the area around the TBA641 audio power amp
was totally charred,cut away the mess and built
a new o/p around a TBA820M.
Seavoice Seafarer RT100 old marine band workhorse
No transmit.
No relay click over on press to talk.
Break in wire at Bulgin connector of the mike.
Remade and filled the contacts area with hotmelt glue to act
as cable anchor.
Sharp SF 7750 photocopier
Intermittently stopping showing fault code H4
The general Sharp reset code Clear repeat 0 Pause 14 did not work.
Near the main hinge at the rear of the m/c is a 2x9 way signal
connector. Disconnecting this ,powering up,off,reconnecting and
powering up reset the H4 condition.Fault was due to dodgy
contacts on the fuser section thermal switch.As not a standard thermal switch
i opened up the available space and put in a standard lower temperature switch
(as not physically rubbing on the fuser roller)
I've since found the reset code for this m/c is CP0P Clear,Pause,0,Pause.Other
Sharp reset codes for different m/cs are CROP13,C00C also sometimes these codes
preceeded by pressing the print button.
Incidently the
page count on this m/c is by pressing 0 continuouslly for
a sequence of 3 two figure numbers.
Simda 3215/2 slide projector
No mechanical slide transfer mechanism also broken focus adjust.
The main mechanical drive ,not the carousel stepper or inter-slide
black-out function,was mechanically broken.The main cam of black plastic
was broken diametrically initiated at the centre D shaped steel spindle.
This plastic was not fibre reinforced ;there was enough space to glue back
together with hot-melt string and reinforce the boss with a couple of small
cable ties.Similarly the plastic closure on the focus knob spindle had sheared off.
Made a steel bracket anchored to the nearby chassis screw and packed
out with a block of PTFE to bear against the focus spindle.Crude in both
cases but stronger than the original poor design.
Tektronix 4663 X-Y plotter, c 1980
I own one of these monsters and thought I would
just make an internet notice. I only have a user manual
rather than repair manual. But it may be useful for someone
out there with a non-working one to be in contact with
someone with a working one. I do have a 4662 repair manual
which superficially is a scaled down 4663 but don't know
about the electronics 4662 to 4663.
Toshiba BD5120 photocopier
Gradual loss of image to no image in about 20 pages.
Failure of the driver to the 24V motor pushing the toner from
the toner bottle,both leads at 24V at all times.
The monitoring of the toner sensor / switch would apparently
be 2 stage first voltage switches on the 24V line once every page
if sensed lack of toner and then a higher voltage sets the 24V line for a specific
time and then if Voltage not dropped back to low voltage disables the m/c.
The first stage was being triggered too late for the time slot to
pass enough toner into the m/c to replenish,so adjustment was needed.
Also probably due to owner fiddling there would appear to be no way of
holding the complete developer section onto the rear cog train so
was sliding to front panel side and disengaging drive so attached a
haevy duty compression spring that pushed against the main front access door.
Toshiba BD5120 photocopier
Total loss of image particularly at switch on.
By switching off m/c half way through a cycle the latent image is on
the OPC but no transfer voltage. To gain access to the HT driver board at the base
of the m/c remove rubber conveyor belt section and dual HT wire carrier. Remove
the nylon standoffs from under the base of the m/c. There are 4 wires that go between
this board to a 4 pole switch assembly that is an interlock for full closure
of top and bottom of m/c near the fuser area. This switch assembly is actuated by
a triangular plate jutting down from the top section of m/c. This is held with one
tapped screw which was loose. Replaced with a through bolt and double nut.
Toshiba BD 5120 photocopier.
Toner going everywhere in the toner hopper area but not into
the archimedean entry. Perished foam that allows the toner
bottle holder to slide into the archimedian position, so
allowing toner to get into the housing .
Toshiba BD 5120 photocopier.
Clattering noise at switch on then engineer spanner symbol and cease.
The paper entry drop down arms would clatter up and down a couple of times
and the cycle would stop there before moving on to the main motor start-up.
Under the toner hopper is a microswitch actuated off the cam/cog that operates
the paper entry arms. Because of spilt toner or wear on between cam position and
uswitch button the system was failing to get a set/reset signal from this uswitch.
Another problem - maybe preceded by rucked paper as that fault
rectified after cure. Main fault was paper jam at O/P LED
lighting but paper stuck at I/P with leading edge near OPC.
Cleaned rubber and clear covered rollers at entry. Also
after cleaning the paper when fed in by hand showed less
resistance to ingress before being rolled in.
Toshiba BD5120 photocopier
Intermittant loud squeal after 10 minutes of operation.
This fault and solution is probably applicable to all
photocopiers. The squeal was so loud and short duration and
no consistent part of the machine cycle. All bearings were
lubricated and no pile of filings to indicate metal rubbing
against metal. Just by listening I could not even determine
whether the squeal was coming from the top or bottom,front
or back of the machine. I obtained a medic's stethoscope and
unscrewed the diaphragm and fixed on a length of polythene
tube. Waving this around the squeal was loudest in the region
of the driven end of the fuser roller and silicon rubber
backing roller. The fuser lamp was slightly off centre inside
the fuser cylinder and presumably after heating for 10 minutes
was sagging and rubbing the cylinder.Propping up the two rear
feet of the machine helped as well.maybe a bent baseplate.
Toshiba BD5120
Document glass leading edge motorised indicator panel
dropped into the path of the travelling mirrror.
Relies on 2 plastic pivot points so just ordinary
leaning on the wrong area can easily break a pivot.
Make up a support from this metal (to clear the mirror)
to support the edge of the pannel.
Toshiba,Gestetner and Mita may have badged the same machines.
Equivalent toner for Toshiba 5110,5120,7610,7720 , Types 64, 80 Universal
is not a useable equivalent to toner for Sharp SF 7300,7320,7350 ,7370
both by Katun , USA. No idea if the proportions are the same but both types contain
Styrene Acrylic Resin, Carbon Black, Polyethylene, with same code numbers
but differing code numbers for the organic pigment component.
The Sharp toner in the Toshiba produces too feint an image for use and
too high a throughput/wasted toner and excess build up of a toner film on the OPC.
LZR1200 (Dataproducts USA) toner required the exposure
setting at the lightest end of scale for image.
Agfa X35 leads to black spots of dumps of toner on image.
Vibrodorm VRT/3 bed vibrator, 1996
Intermittant no control over the controller although
red LED always flashes on r/c, sometimes worked
if r/c right nest to controller.
All IR LEDs checked working.
Used only 6 (12) commands of a SAA3004P.
Assumed firstly it was problem with switch in
r/c battery compartment or recessed on controller box
intermittently swapping code channels,
there for 2 kit use. Problem was due most likely
to corroded sprung DIL socket for the PIC IC ,
replaced with turned pin one.
Volvo ,Sweden 1986 car door speakers
Litz wire problem soldering between tag terminal and cone
Wolsey Spitfire AF0323,electric fence
Internally HT discharging from HT overwind to transformer chassis.
The water ingress seal was compressed so packed out to regain
a seal.The HT overwind at point of arcing was touching the chassis so
forced a steel rule to make a gap between overwind and laminates
and then introduced some thin paxolin (FRPB) sheet.
Computers and related
Acer 950CX power supply ADP 36GB by Delta Electronics.
No o/p.
Short on the o/p,isolated possible culprit / false leads ie low voltage
side of the transformer and one of the electroluytics. After cutting a
couple of traces isolated to one of the diodes in the double centre tapped
high-f rectifier GI UG18DCT. Replaced with a GI SBL1040CT 10 amp device.
Also in passing for anyone with burnt out mosfets they are 2SK2056 and IRF9Z34.
A H Electronics Backpacker 1 Metal Detector.
No function,no audio output at any setting.
Both ICs had the markings ground off ,one leaving a marking of C and the other
a final figure 2. Replaced the DC level amp marked C with a 741C. Note if the outer
casing is too near the large 2.5nH RF choke then no function although OK before
mounting back in the casing.This became an intermittant fault with the machine
only functioning when cold and not when warm. Desoldered the choke and remounted
on the other side of the pcb to cure this odd fault.
Automaston Hopping Bunny toy
Sorry about this one.
After a couple of bars of "music" the bunny should start hopping via
the motor driven rack and half pinion - spring return mechanism but
just cuts out at the point the motor should start.
Probably some current monitor in the circuitry and motor start current
too high and monitor sets the circuit to stand-by mode. Motor worked
fine on external ps,no shorts etc. Added a 2.7 ohm in series with the motor
resistor in series with the motor.
Bios problem with old computer.
I decided to use my old computer as a file back-up.
So gave it a present of a new 40GB hard disk. But
whatever I did I could not Fdisk / Format to greater than 6.9G.
My two tame pc experts couldn't help. I decided it was a
problem with the Bios, no website for the motherboard
manufacturer and couldn't find a site for updated bios.
If I went into the bios / Standard bios settings I could
change the HD parameters in user option. Too
large a setting and available space would be even less
than 6.9G , one time only 45M.
Gradually increasing (by suck it and see )
cylinders and sector numbers 2100 cylinders and 189 sectors
would give 31GB and 21,500 or 192 sectors would not work.
So settled on 31GB. Then found a "hard disk exerciser" discex.exe
as discex.zip to check if non-standard settings would throw a wobbly
and it didn't.
COMMODORE A 500 ps
No output.
470Kohm dropper feeding control cct was open circuit.
NB the 3 pin regulator on the o/p side is used as a voltage
monitor.
Commodore C128
Malfunctioning key
The usual problem with conductive rubber keys.Repaired as in repair tips for
repairing conductive pads but because of the extended resistance between 2
contact pads on these keys used aluminium foil instead of compressed conductive foam.
Compaq portable 3, PC,failed dedicated ps
Someone's cherished early LCD screen computer that i would have called a luggable
rather than portable. Previously owned by a famous scriptwriter
complete with the drafts of some of his plays.
For diagnosing fault powered from variac at 100v ,half normal mains for safety.
It was cycling every 5 seconds or so to kick in but not maintain supply.
One of the 2 optoisolators for the half second when ps functioning was reverse driven off. Bypassing
the output C-E transistor
by 5K allowed the supply to fuction but as drawing 0.5 amp from the mains at half supply voltage so
only left on a second intermittently. Enough to show problem with -12V rail. Not the 7912 1
amp regulator but the 3amp high f rectifier supplying it shorted.
Incidently there are high V supply rails for this sort of machine as well as 5,12 and -12V rails
measued without load as 200v,220V and 5V going to the screen
Computer mouse problem
Where cleaning has no more effect on curing lack of positional
control of the mouse.
Remove the ball and in the space above the ball mount a piece of foam covered
in plumbers PTFE tape so when ball is replaced there is something more tangible
than self weight to keep the ball in contact with the mat .
Connector repair dodge/bodge for broken pin(s)
on those 15 way high density D plugs
on monitors etc.
I gather this is
a fairly frequent problem - i don't
as a rule repair PC equpt. The moulded
on plastic connectors that would be a pain
to break into to trace the wiring and
solder on a replacement.
Obtain 2 solder type 15 way high density D cnnectors
one plug, one socket to make a back to
back "adaptor" then plug and screw
down the socket
onto the damaged plug.
23swg tinned copper wire is ideal to
wire in between. 5 short and ten long
pieces. To solder the central pins you
need a filed down solder iron tip.
Before soldering the second connector
(socket) reverse and introduce the free
ends of copper wire into the socket holes
to align the copper neatly.
Swathe in hot melt glue to hold in
register before turning round and soldering
on the socket.
Firstly use a cut down
high density crimp type plug pin
swaged/crimped onto the stump of the broken pin
then soldered as well. Pack out a bit
in other parts of the mating surface
area to allow for the swaged lump. The "repaired"
section will not of course mate fully home
so needs bolting down to the original plug
with the retainers extended with small stud
and hex stub anchors. Bathe back to back
bit fully in hotmelt glue leaving space for more retaining stubs
to be tightened to the pc
Dell Inspiron 7000
To use a HD that is a snug fit in the Dell recess
and cannot use a proprietary caddy and adaptor.
Adaptor for 2x22 way 2mm pitch HDD connector to
the sort of 2mm pitch double sided edge connector fingers of the Dell
Remove the Dell battery.
Find 22 plus 1 DIN4162 phosphor bronze receptacle pins
Grind off the stick out retainer arms . Feed over some
cord or something that will stiffen on application of super
glue. Cut some 1mm lengths of 1mm silicone sleeving .
With another pin flatten the splayed ends so you can feed
a sleeving ring over, then open the blades with a pin to allow
the , to be used pin , inside and let the
sleeve back onto the pin, to get sleeving over
the splayed out ends. Repeat 22 times. Align them all on
a steel ruler , apply super glue to the cord and then epoxy
round enough to hold all together.
http://home.graffiti.net/syxygy:graffiti.net/2mm_pitch_adaptor.jpg
Next time I will change the order, a line of hotmelt string
to keep in place, pull the cord tightish , then at superglue,
the epoxy. So avoid the snaking cord , in that image.
When set, replace the steel ruler with a bit of old credit card plastic
for convenience
From turned pin DIL sockets cut away 44 pins and grind back
the protruding rings so can slide onto the HD pin array
without shorting. Use a scrap HD for alignment purposes , (
beware some pins may be interconnected).
Grind away the crimp/solder sections
of the DIN pins and now isolated conductors, bend a bit and solder
to the DIL pins. Before soldering the 2 sections together
add some Kapton tape to divide the pairs of lines of pins ,
to avoid solder bridges , inaccessible to remedy
When all aligned then add some plastic
to fit in the outer shell of the Dell and can be glued
to the adaptor. Inside a part mold of
some sort bulk up the adaptor with hot melt glue or filled
epoxy. Check for shorts after soldering and before final
gluing and again before use.
Dell laptop ps PA 16, F970, 3A, 19V dc
Broken lead at the DC power connector.
Lucky for owner any short at point of
breaking did not destroy the ps or pc.
Because of the ferrite ring not
enough room to put on a new connector with
cable protector protrusion.
Remade connection over the break, well
insulated and then packed out with hot-melt
covered with spiral wrap, in all enough
to allow large piece of heat shrink
over to cover the ferrite and the connector
and lead to shrink down to one long
conector in effect.
Diode test at o/p one way 0.25V or so
and other way after charging a cap about 1.4V.
Dialogue box problem in windows.
Especially freeware applications which assume
a standard screen size/resolution, yours is smaller.
The box is too large on the screen so the bottom
lie with OK,Close, Cancel buttons or whatever is
down below the bottom edge of the pc display.
Pressing Alt-O,Alt-S or any such combination
does not work. Try pressing the Tab key
and step through to the last visible entry box
and then one more , to the first unseen one ,
and press the enter key
email problem
This might as well go on the file as it might help others.
I run an obscure internet specialised site and part of the activity is
circulating over 100 people in an email circulation list. In July 2002
someone in the group but never identified had a rogue server/settings .
His machine/network was echoing each incoming message to up to 12 times
a day to others in the group.
All of them thinking the repeats were a system fault at my end so i
revealed the hidden headers on these echoed messages coming back to me.
To reveal the full hidden header if you use Outlook Express goto File /
properties / details / highlight (mouse click and drag) then Control+C to
copy and then paste to a text file. Some of the identifying features were
server11.safepages.com , lialserver , nas22.somerville1.ma.us.da.qwest.net
To get round the problem i used Blind Cc (BCc) instead of ordinary Cc
and in the text of the email which contained everyone's email address within the
group i replaced @ with ^. Apparently this is standard practise to use Blind Copy Circulate
but no one had told me. With hindsight it now seems obvious the rogue recipient had lialinc.com
as email address which correlated with lialserver. They had a mail box that was full
and echoing input back to the internet and to internal servers which presumably gradually
filled up more internal mailboxes for a runaway closed loop. The company closed
down for holidays and the problem built up with no one to correct it.
Epson Stylus color 800
Somethoing fell on the corner over the ps,
would not index , leaving power and 2 lower LED lit
and the top one flashing.
Paper grabber arm was not rotating.
Removed the 4 screws to remove top cover
and unstuck and unplugged the ribbon.
A loose black cog in the space next to the ps
and the top slotted opto mount near the ps was bent.
The black cog had burst off the end of the long black
shaft that caries the paper inlet rubber cams.
The whole paper carrier tray was loose towards the ps
end as the retaining boss had sheared, undoing the
other special bolt allowed that to be removed.
Note the position where the cog fixes, indexed to the
rod and mark both before reassembling.
Pushing the whole paper carier tray ps-wards allowed
a peg or 2 to engage to locate and locked
in place at the other end after replacing that screw and
swathing in hot-melt glue.
So it would be possible in other situations to cut that
boss at the ps end to avoid removing the ps to remove
the paper holding mechanism.
The 3 wires go to an indexing opto on the end away
from the ps.
The previous owner, now throwing it out, had put the printer in the loft
when the black started running out a few years back.
No trace of black on refilling and many blocked jets on the R,G,B
Doing the utility cleaning dance made no difference.
Manually sliding the carriage over 6 sheets of cardboard soaked in ammonia
solution made no difference, same with ammonia in the docking/cleaning
hoppers.
It is quite easy to remove the large round slide-way bar on these and turn
the inkjet heads upside down.
Then putting enough ammonia solution to cover to meniscus level, the black
and RGB heads, and very lightly moving a piece of cardboard around in the
ammonia water cleared the blocked RGB jets but no change on the black.
I cut a couple of small squares of sewing/habberdashers/miliners felt,
intending to lay both on the B&W cleaning tank but unpowered moving the
carrier across, one transferred and landed neatly on the RYB (not RGB of
coarse) tank so left as is. Placed half a drinking straw of ammonia solution
on each piece of felt, moved the carrier fully to the right to engage the
tanks uplift mechanism and left overnight.
Bit of a puddle of ink in the base this morning but on running the ROM dump
print test all is working fine except two jets on the black delivery - I can
live with that.
Had been in a loft for over 3 years.
Favicon creation
No good just creating a 16 x 16 pixel GIF and changing .gif
to .ico as the first 3 characters etc in the file remain set to "GIF".
Easiest solution I found was to download small viewer and file converter
IrfanView , load as gif or JPG and save as ico.
FSP 250-60GTV atx pc ps dead not even a flick of the ps fan
Chicken or egg
There are 3 HF transformers and an opto-isolator bridging the HV and LV
sides.
The startup oscillator, on the HV side, is a KA1H0165R whose o/p crosses the
divide to give a Vcc of 12V on the main SMPS controller a KA3511DS, both
datasheets downloaded.
This controller o/p should then cross the divide to drive the HV side main
oscillator to drive the main transformer back to the LV side supply rails.
The SMPS "flag" output pin goes high meaning no-function and no o/p pulses
for either push-pull output of this KA3511.
As the KA3511 monitors over-voltage, and more to this point, under-voltage
of the supply rails , how should it ever get started if it never outputs any
main drive pulses, so no main supply rails.
I can see the one large and two small HF transformers tied up with the above
process.
The opto would seem to link, DC fashion, from the 3.3V rail back to the
feedback pin of the low power startup IC to shut that one down.
This IC, with the reservoir caps, will keep the main smps IC running for 10
seconds after removing the mains supply (in the present unfunctional as a ps
state)
With the KA3511DS connected purely from a 12V bench supply
5.6K from 12V to pin4
REM low via 50R
pin 7 and pin 9 then 3.5V
Q1,Q2 both still 2.2V
did not get around to fudging 3.3,5,12V on p15,16,17 as realised
it was a problem in the wiring to the pc front sw not a ps fault.
20 pin ps connector P1, pin14 (green) was not going to 0
was the trouble, there was the standby 5V on pin 9 (purple)
and no ps fan on in standby.
Irfanview
Beware of changing JPG compression factor and then not remembering
what it was as this app. does not remember and
sets the default as the previous useage.
If likely to be changing this factor then keep
copies of previous before re-working an image.
To copy/paste and merge. Select area of one image , copy,
then open similar area box in second image, paste, adjust
perimeter to match then repaste, repeat until fitting
and then cancel the box to fix in.
Indexing large pdf files on CDROMs.
A number of CDroms at a radio rally being almost given away
as there was no externally accessible indexing - you could not
see if an IC was included without loading up each CD.
Widows explorer can "see" specific words in a pdf file.
FoxitReader pdf reader to read whats there, where the index/cross references
were.
pdf2text to convert the first 15 , 50 or whatever pages to text.
It loses spaces but that doesn't matter in this use for keyword indexing.
Unfortunately 2 pdf files were 1,500 pages long with the index at the end
so had to go away for 1/4 hour and then delete 1,450 small text files as you
cannot preset pages on the free pdf2text version.
Then used AF5 batch file-renamer to put some structure to the file names.
(aside, A.F.5 is useful for creating a text file of a large batch of file names -
AF5 /Add/ mouse click [move cursor] shift+mouse click [to highlight blocks of files] and then [select all/batch/save as ] to save as a text file)
So I won't be throwing them out now they are usable.
No wonder someone was disposing of them at a radio rally for next to nothing
as useless before externally indexing as plain old text that is easily searched
before loading up the relevant CD.
Problem downloading emails from freeserve/fsnet, maybe orange/wanadoo.
If you get error message
"... Server Response: ' Disconnect because authentication to back server is too long', Port: 110 ..."
Then on repeated attempts you get
"... Server Response: '-ERR [IN-USE] Unable to lock maildrop' ..."
telling you you have the wrong password, but you know
full well its a problem at their end.
Especially if still a problem trying to browser access via likes of
http://www.mail2web.com/
Firstly go to
Tools/accounts/mail/properties/advanced/server timeouts
and increase the time.
Secondly
Leave a gap of about 3 minutes or so before attempting
to repeat access, go away and do some browsing or something else in the meantime.
Makes no difference , what time of day or night, same deliberate? system delay,
2, minutes is too short and 4 minutes too long.
Foreign unicode script on a file which corrupted the Google cached version
of otherwise English page.
I downloaded Hex Editor XVI32 from
http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm
That allowed me to remove the 2 characters ÿþ / hex FE,FF / ASCII 255,266 / y diaresis and p with
ascender that clogs up the front of the file, which you cannot see let alone
edit out in Word or Notepad.
Apparently this is appended to denote the file contains unicode,
the BOM Byte Order Mark and also Zero Width Non-Breaking
Space (ZWNBSP) . Google cached interprets this as inter-character spaces throughout
the cached version and consequential loss of HTML action. The preview pane on Google
is also corrupted because of the spaces mangling HTML. I'm surprised there is
nothing on Google FAQs pages about this. Putting "ÿþ" and "h t m l" in Google
produced 206,000 hits. Randomly selecting 5x10 of those showed 44 were mangled so
perhaps about 180,00 such affected files.
With Hex editor also "Replace All " inter-character 00 to (blank/empty) which also
reduces the file size by half.
Then a matter of converting the foreign code characters like hex
code [ 05D2 ] to decimal/decade code [ & # 1 4 9 0 ; (no spaces) ] which Google Cached seems to like and also
browsers. For smallish amounts of text for conversion: - in Word convert all
end of line ^p to * , to concattenate and then break up to lines of about 100 characters.
Submit each line in turn to Google ( much more than 100 is a Google illegal op)
and it returns search string as ....; form, highlight and copy back.
In Word convert back * to ^p , saving as non-unicode text in a non-unicode HTML file
and compare the result when viewed on a browser with a .png, .gif ,
or .jpg form of the script to check. Then add to English file.
For a load of foreign text use the block routine in XVI32
and copy Hex to Word as a .txt file after removing FE,FF and converting all the 00 to 0D0A
and any spaces/punctuation to 2020 or whatever as 4 characters.
Giving a file of lines of 4 characters after converting 0D0A to ^p.
Then make a macro for converting adjascent
quad alphanumeric characters to decimal numeric. Finally changing ^p to ; and tidying up punctuation etc.
I used this Yale file as a model which reads correctly as English plus foreign script on a browser and is
cached by Google correctly
http://pclt.cis.yale.edu/pclt/encoding/
and a bare minimum of HTML eg not even LANG designation.
So with hindsight just save the foreign Hex text as unicode file and convert
to decimal/decade form before adding to full English file and then can continue to save
as ANSI and retain correct caching of HTML on Google.
For anyone else with this problem but where they have no foreign
text on their file and accidently saved their file as Unicode.
Without a Hex Editor you will not see the ÿþ or double zeros that Google sees.
Suggestion: rename your file from XYZ.htm to XYZ_old.htm
View it in Internet Explorer and click View / Source,
"Select All" the text and copy to notepad and name
the file XYZ.htm saving as ANSI and not Unicode.
If you want to check the file then download the XVI32 hex editor
( link above) - its only about 500KByte so
only takes a couple of minutes and compare the two versions of your file.
Google no longer indexing files in list form
After 10 years of indexing my files , only more text like files
continue to be indexed, same with MSN etc but not Gigablast, Ask etc.
What is going on ?
If you put a few words like
stilsons pilewound
into Google you should find my UK/USA tools translator site
http://www.divdev.fsnet.co.uk/tool_terms.htm
but Google is no longer indexing it.
If you know what site its on ie adding
site:divdev.fsnet.co.uk
in the searchbox then the results appear as
These search terms have been highlighted:
These terms only appear in links pointing to this page:
or
These terms only appear in links pointing to this page:
despite the words being in the text of that page
I've identified some issues associated with the PRE function and will
address those first as it is, in my case, affecting files that are basically
listings. For my own convenience, looking in a text reader most of the time,
I wanted the files to be readable in a text reader and browser
simultaneously.
ie not a string of characters with no end of line characters. line breaks
and cluttered with markup characters.
Another point is my files have basically had the same structure for 10 years
with just the odd additions or deletions. Somrthing changed with
searchengine acceptance end 2007/start 2008.
Returned to Google indexing after a month
and a number of crawl visits.
Turned out the BODY html function was missing, META statements
should have been in the HEAD section and the problem with
the PRE function was that there were HTML functions in
between PRE and /PRE which is not allowed.
Eventually checked out with
http://www.htmlvalidator.com/
after adding html 3.2 !doctype statement at top
but not via
http://validator.w3.org/
as too many URLs with ? etc in the URL
Hi-Grade LM 156$, 1995, pc CRT monitor
Wavering brightness , going up and down fairly slowly ie thermally , with basic
image itself rock steady.
Remove the 2 obvious rear screws and then prize open at the top
where there are 2 square notches. Retaining flat-U clip about
1/2 inch either side of the notch and 1 inch in.
Cleaned the CRT pins and redid all the CRT socket
soplder points although nothing obviously wrong.
So much for thermally derived fault, looks as though it was
poor plug/socket connection on the back of the pc, some
capacitive effect slowing things down ?
HP Deskjet 660
How to remove plastic casing.
Rear panel covering main circuit board - push a rod into each of the two
holes in the baseplate to release that part.
For rest of cover first remove the small half inch strip at the left hand base by
lifting and pushing to the front of the m/c,you can see the "hook " pieces
that lock this fillet into place by removing the paper carrier and viewing
into the left side interior. That unlocks the main cover which you release by
poking a screwdriver in the slots in the base plate.
HP Deskjet 720C no paper roller motor action.
Someone had managed to wrench one of the 2 pivotting paper guides.
These have "cam" end actuators and one had ended up above the
actuating arm that runs parallel to the main paper rollers. This could
be wrenched back again but the misplaced cam had jammed the secondary
cog system and stalled the drive motor and knocked out the driver chip.
Motor OK but 44 pin plcc Texas SN104558FNHR running hot and no
output drive to the motor. Could not find a replacement so no repair.
Hyundai HMM413 VGA monitor.
Loss of image but would momentarily flare to proper brightness at switch off.
Mechanically broken preset marked sub-bright at rear of casing.
Replaced 500K satisfactorily with a 100K preset.
Inno3d tornado geforce4 titanium video card
Low resolution text screen reads alright but after switching to Windows
high resolution breaks into an overlaid multiple image of wrong line rate.
Bearing on the fan was knackered and would stall.
JPG problems of apparently truncated jpegs
They display the perhaps about 80 percent of the original on
Firefox or IE (same cut off point in each browser) but you can't save as jpeg. You go through the motions of
saving as jpeg , no error message appears, but nothing saved in the relevant
directory. Other than saving to file as a rather useless .prn, printing off
the screen and scanning in , or photoing off the screen and montaging,
is there a work-around to this.
One of those mysteries of the internet/applications.
The emailed files were to a browser based account of mine that does not
have filters on it. Downloading to firefox or IE produced truncated but
viewable images that could not be saved to disc.
Forwarding those attachements from browser account to my main email account,
with filters temporarily lifted to download, then saving those attachements
to disc as jpg, then all 5 were readable ,complete un-truncated pages. I've
never had to do that before.
Modem - loss of modem speaker
As a result of a rogue dialler the modem speaker was disabled
so could no longer hear the FSK dial out and ingrained familiar
and so consoling distinctive beep/chime response.
Disinfected but speaker still switched off regardless of what the options
about volume were saying.In
Control Panel
Phone & Modem Options
Properties
Advanced
Extra Settings was
S7=240
I changed it to
S7=240,M1
then Change Default
and
produced SD & RD LEDs flashing and "connection was closed".
M and S are Hayes modem codes.
Removing the comma limiter leaving just
S7=240 M1
brought the modem speaker back to life and normal service resumed
Modem - Failure of external computer modem.
Resulting from interupted power to the modem. After sorting out low voltage
supply ,LEDs lit on the modem but no one was home. Computer unable to
make connection to modem. Standing 50V on the phone line OK, on opening the modem
there were 12V,-12V and 5V rails so probably OK. Put an RS 232 LED checker in line with the
pc to modem lead. From the pc active negative on lines (pin) - TD (2), RTS (4) and DTR (20)
and on the modem on its own active positive on CTS (5), DSR (6) and active negative
on RD (3), DCR (8) ,so all ok so far . No flickering LEDs when clicking to dial out.
Windows 2000 has a failing (feature) of "disconnecting" modems
if found not powered up when the pc is powered up and does not advice you of this when repowering the pc.
Windows 98 does not have this "feature".
Mouse troubles
Fails to move cursor unidirectionally
That is moves easily ,say,l-r but not r-l or up-down
but not down-up.Reduce the spring action on the third
dummy balancing rotating wheel that pushes against
the mouse ball.
Nero 6 install of CD writer
CD writer not recognised, the relevant last page before
is whited out in the drive pannel and "Burn" button
greyed out.
Go More/Configure/ expert features
Tick "Enable all suoorted recorder formats
for the image recoreder".
If the apply/ok button is missing below the bottom
edge of the screen press ALT-K for OK ,
other panes it is ALT-O
Nintendo Game boy DMG 01
One line and click on switch on then a few lines and another click then nothing.
The DC top DC converter seemed to be working 6V to 5V and -26V.
Did all usual checks making and breaking connector,switches
etc ,reassembled and worked.Possibly poor ps input socket as similar
result is obtained with using a current limited 6V suply as original fault.
Nintendo Gameboy DMG01
Zilch on battery power
New set of ni-cads had slightly smaller positive
end terminals and not engaging with the contacts.
Packed out behind the interconnect busses and removed
part of the plastic surround to the 6V terminal to make
consistent contact.
Potrans ITE power supply for Time Cybernote 953E laptop
Dead ps due to short in DC lead at point of exit from
the ps box due yet again to over tidy owner (always seems to
be female) wrapping the cord tightly around the ps case.
Replaced with high current dual lead rather than co-ax
Relisys TE770 monitor
Only 3 years old, LED blinking and relay clicking on and off.
The "on/off" switch short-circuits the mains
SMPS side of the opto isolator
to switch "off" the monitor, bit unusual.
Stable 7V or so on the driver side of the opto-isolator
and a 7805 gives a stable 5V for the micro area.
Failed to repair, the NT6827 OSD chip was
loading down the 5V line. Cutting the rail to that
chip meant the monitor would power up as far as high V
generation but nothing on screen. Forcing the 3 RGB
lines from that chip made no difference.
Rogue Dialler and killed modem speaker
Rogue dialler but first indication was the
dialling & beep/chime acknowledgement disappeared
from modem. Bit of a giveaway really.
Nothing I could do in modem options would bring
it back.
In rasphone.pbk Speaker=1 and Dialmode=1 seemed
correct.
In Control Panel
Phone & Modem Options
Properties / Advanced / Extra Settings was
S7=240
As this was a Hayes code , I changed it to
S7=240,M1
then Change Default
and
produced SD & RD modem LEDs alternate flashing and "connection was
closed" dialogue box.
Removing the comma limiter leaving just
S7=240 M1
brought the modem speaker back to life and
normal service resumed.
rnaapp.exe and Outlook Express problem
leading to an assortment of error messages and
dropped dialup connection when connectinfg to
first or server or one, later, further down the connections.
error 678
The computer you are dialing in to is not answering.
error 720
error 645
Dial-Up Networking could not complete the connection to the server.
Check your configuration and try the connection again.
"Another program is dialing the selected connection" etc
Some carry-over data gets corrupted from a
previous session and the rnaapp thinks there already
is a connection when you dial up, fist time of a new session.
Instead of uninstalling etc just try a change
of operational sequence.
Dialup as the first application and then open OE.
If composing emails/replies prior to dialup , then
close down OE and then dial up.
Shotz Smart Digital Camera ,SS 2000, installing on Windows 98SE
A page relating to problems with 98SE came with the instructions.
RPC stub error relating to oleaut.dll dating, the solution was
supposed to be, download files from their site rather than their CDROM.
This may well be possible but I could not make it work, first time
used a USB port on this pc compounding matters.
Downloaded mcrepair.exe from microsoft and selected backdating
option. Then, as I don't consider myself stupid a tip relating
to Microsoft "Scanners and Cameras" installation wizard.
I was exiting at point where you have to select port Serial 1 or 2
or Parallel port - no USB showing up althogh apparently installed.
Ignore, by selecting Parallel, and the camera drivers can be
installed employing USB by default anyway.
For people not often using the camera - notes
1/ When starting to download the software is not specific
and you have to select from menu. There is no specific SS 2000
to select and thinking SS=Single Shotz then leads to "no device found"
error - SS=Smart Shotz.
2/ The other default selection is "download and delete camera memory",
you have to actively select the other option to retain camera contents
which seems bad arrangement.
Shotz Smart Digital Camera ,SS 2000
Converting the "shutter release" for macro photography.
Too much pressure required to manually press the release switch
leading to camera shake in a magnified set-up.
Remove 5 obvious screws plus the one under the battery cover.
Pull the cover off and unattach the sounder, incidently the same process
to put an external break in the line to the sounder for covert use of camera.
Remove screw through internal battery holder and the 2 near the viewfinder
and pull away from the USB/AV socket hole and bend out the chrome section
to free the plastic lugs
so both PCB sections can be removed in one for minimal disturbance to
the boards. Remove the now loose AV rubber cover,
and viewfinder.
A lead to the earthy side of the switch is easy but the other side needs
finely melting away some of the plastic of the switch to expose
the contact to solder to.
Find a space to drill 2 holes through the casing to mount 2 connectors
from a butchered turned pin DIL socket for external connection
in parallel to the switch
Twinhead Supernote SX laptop / notebook computer.
I never powered up at first sight as the ribbon cable to the LCD screen was
obviously damaged so don't know what the screen appearance was. Usual long term
flexure at the hinge problem. Replaced the phenolic
brown section of the ribbon to the LCD with standard ribbon cable soldered at one end to
the sort of in line connector in the hinge area and the solder points on the pcb connector
on the daughter board. Could not find much component level info on laptops so here is
some further detail. To open the screen surround; remove the Twinhead label and 3 rubber
bumpers. When surround removed refix the small hinge side back to the body. To remove
the keyboard undo screws and 2 pot knobs and unclip the surround from left and space bar edges and then pull
and lift away from the screen end. The 3V memory battery is located under the cartouche shaped
label under the m/c.
High voltage back light supply. Comes on a couple of seconds after main board power-up.
Mounted under screen in raised pod. 4 wires in - 2 wires out. The T5001 TI SMD in operation
had pin1 6.7V,p2 12.4V,p3 1.6,p4 1.6,p5 .7,p6 3V,p7 1.6V,p8 .5V measured to battery neg.
12Volt pulses on Tx primary/C8 Cap of about 40 KHz. Putting DVM (2KVolt range) on the Tx o/p
loaded and stopped back light. Connected in series between the
2 backlight wires 100 M ohm,1N4006 and 220nF and measured with DVM
voltage over 220nF,should have used high f rectifier but never mind. On first applying DVM
measured rectified voltage greater than 4V dropping to steady state
of 1.1 V all
with the LCD illuminated at the same time.
The secondary resistance of the TX was 215 ohm so step up pulse voltages must
be well in the hundreds (3KV rating capacitor on output).
Changing brightness reduces the pulse amplitude.
With drive disconnected
the 2 wires to the backlight registered 55pF on a 1KHz capacitor meter and no apparent
resistance on 20M DVM range.
On the main board the Linear Technology LT1170CT showed 1.6,1.7,.4,5.4,5.4 volts
relative to battery negative. CMOS setup for Conner CP2064 was spare type number
with 823 cyl,4 heads,0 pre,0 LZ,sec 38
Windows SP4 Service Pack installed - then near dead pc
Win2k installed SP4 fine but on reboot it gets to the flying window pane
and then shuts down the power supply just like pressing the machine reset
button.
Then just cycles through this route and never opens windows.
Same trying "Safe Mode" or other f8 options,
also "repair" from original CD or from the 4 floppy start up / boot disks
does the same.
Can only put old DOS on a: drive but cannot access c:
in any way.
Recovery Console just allowed to check
the c: file structure and nothing much else
Tried fixboot , fixmbr from the CD but still no windows access in safe mode.
HD plugged in as D: on a friend's pc with XP, same file structure.
Didn't have to change BIOS setting or anything other than a virus scan,
to copy across to CD-rom
Wxtide32 Tide calculator.
If your pc keeps latching up if you stray too
far back or forwards from the current date try
changing your pc clock to about the date of interest
and then start the program.
Zoom 286A modem
random flashing LEDs then nothing
Was powered up from 9V ac , not 9V dc.
Replaced the 7805 regulator, beware multilayer board
Domestic and Miscellany
Amstrad AB800 cordless phone handset
Telescopic aerial dropped out.
As the owner in his efforts to get the handset appart so it
looked as though it was eaten by a dog it is probably worth explaining
how to get inside.Remove battery cover then unplug and remove battery
and the ellusive screw is under the battery. No lock nut on the base of
the aerial so free to unscrew so reconnected and locked in place with
liberal dose of hot-melt glue.
Asda MDS V3 , 2008
its possible to add in a second Scart
and so feed both a TV and recorder. Undo case screw and knife
blade at Scart to prize open. Cut out "punch-out"
for the second scart.
Jumpered lines 1,3,4, 17,19,21 and glued in box,
and no mismatch problems on this pair of TV and recorder.
Nice obvious on/standby LED indication on these and echoing of zapper signal
and retention of settings on power off , so can be used atached to a
reserve/second recorder, without TV, for simple recording, after initial
installation. Add an earpiece to audio compare
with TV on same channel. One large NXP philips chip
and not much else other than memory and tuner in these.
power consumption 12.2W but 10.4W on standby, ignoring ps losses, so broke into
power socket and wired in a switch. Unfortunately the channel
that comes up at switch on is not the one at switch off
or the "recall" channel but tends to be the same as previously
the initial channel, but not always.
One great plus for this cheapest of digi-boxes - so far
anyway, its immune to having the EPG remotely
updated, outside your control, in the middle of
the night when you are recording a film.
With another crap one next day 20 minutes
of blank recording while a load of graphics laden
ads are downloaded because there is no one there
to disrupt the default of auto downlaod.
This ASDA one works from start and does not
try downloading the EPG crap from power up
and consequential 20 minute lock out.
Bicycle pedal crank (aluminium cranks on squared steel shaft) removal.
Where the Al sort of welds itself to the steel and riding around with the
retaining nut loose will not free up this join.
The chainwheel side removed satisfactorily, with heating as well,
with a standard large bearing/hub-puller as the puller
tangs can settle around inside parts of the chainwheel. But the
left hand crank is not so amenable.
Found this maybe home-made tool obviously not designed
for bike use as the U slot was too big and needed to packed out with
a couple of bars straddling the slot. I will describe the tool
in case a standard tool. For bike use all dimensions except the
screw parts could be smaller , certainly the circle ended slot reduced to
3/4 to 1 inch wide .
2 off 1/4 inch plates 3.5 inch square. Near to each corner 4 long bolts
3/8 inch diameter with covering 1/2 inch hollow rods 4 inch long so forming a cube shape.
One plate having a U slot 1.5 inches width ending in circle centred
on centre of plate. The centre of the other plate a steel block
3/4 inch thick and 1.5 inch sides welded to this plate. Then that plate and block
tapped with thread to take a half-inch diameter stud part of a long bolt.
On the external part of this stud a nut was somehow fixed without
welding so a socket wrench could act on it, leaving some exposed thread so could
be hammered. I don't see why this nut could not be welded to the thread.
On the bike , slacken the recessed nut about one turn.
Fit this extractor around and wind up using socket wrench.
Keep the pedals on to apply back torque.
The slackened nut will protect the thread and localise
the central extractor stud. Unlikely to free even with a lot
of force. Don't start adding scaffold tube. Heat the aluminium
up with a butane blow lamp and at some point there
should be aloud crack as the seizure breaks.
Reminder: Left hand pedals use left hand thread so 'tighten'
up to undo, if that makes sense.
Bicycle pedal problem.
Because of formulation of 'rubber'on pedal and
shoes there is not enough frivtion and consequentially
a high risk of a foot slipping off a pedal.
Obtain a motor-cycle inner-tube and cut off a
inch wide or so bands and stretch over each pedal.
More bike tips.
On the cheek straps of helmets paint the inner
surface of the straps a contrasting colour so its
a lot easier unravelling each time of putting on.
For the simple mechanical odometer/tripmeter
devices - for a lost activation pin that is
fixed to a spoke - brass ground/earth terminals
that are used in elctrical wiring are excellent.
Just cut a slot in the barrel to slide over the spoke.
Once a chain revolution at one point in the chain it takes up the
set of the chainwheel, because of a tight link,
rather than hangs loose through the derailleur
and so makes a clatter noise through the derailleur.
No tooth jumping for it is pulled straight in the forced part of the chain.
All you need is a pair of carrier bags as gloves and a bit of chalk to mark the offending
link/s and gradually increase the amount of hand force applied each attempt.
Firmly hold the chain either side of the tight link
and bend horizontally one way and then the other.
The chain does not collapse out of line vertically when so bending laterally.
New bike chain on old cogs.
Slack part of chain riding up over the chain wheel and slipping.
Try holding back the derailleur arm with some stout
bungey cord upwards and rearwards to rear carrier and keeping
in place with a couple of cable ties. If extra tension
on the lowermost part of the chain stops the slippage,
keep the bungey there for a few weeks until all gets bedded in.
Tyre pressure indication , without using a pump and gauge.
I'm fine with finger pressure across tyre sidewalls
if there is definitely a puncture but what about
slow punctures. Is the tyre pressure just a bit less
than it was a week ago? - I never can tell.
Bicycle bottom bracket C spanner and a 10Kg spring
gauge. Hook the C over the tyre so the protruding nib
engages with the middle of the side of the tyre.
Connect the hook of the spring gauge to the other end of
spanner and pull the nib into the tyre.
The spring reading will rise gradually to some point
when the curve of the C hits the tyre and the force
goes up sharply. Note the force just prior to this
large increase.
One pump for Schrader and Presta bike valves
If you end up with both types of innertube.
That is Schrader (car type) and Presta (captive
lock down knurled nut) and don't want to
cary around 2 pumps.
Assuming you have a Presta type pump then rob the
attachement end off a car tyre pump and a Presta
valve from an old inner tube. Hack saw off the flared
end of the brass, release the captive nut. Cover the thread with PTFE tape
and turn/push in half and half two pieces
of reinforced polythene tube or similar to make
a non return valve. Fit half a Prestra type adapter
to one piece of tube and the car pump piece to
the other. Cover each joint with a wrap around
type Jubilee clip (worm drive hose clip ), not the type that leaves a
gap under the screw. For the opposite
ie a car type footpump then cut the presta end
off a non-cloth covered polythene tube
part of a hand pump and push into
the car type connector, it may hold well
enough when the groipping lever is rotated.
Snot filled bicycle inner tubes - whats the secret ?
I can see part of it is pumping up after puncture and riding or at least
upturning bike and rotating the wheel to spin the snot around to replace
leakage over puncture hole.
What other tips ? and when do you concede defeat (re-opening
puncture/deflation) and
know there will never be a reliable reseal ?
One rule of thumb from recent experience.
If you can hear air coming through the puncture , without having to put your
ear near any part of the tyre, then it will not form a permanent seal.
Next problem, how to avoid the snot from interfering with patching before
re-use. For puncture repair (useful for normal tubes also)
use a cylindrical centride burr in a Dremmel to abraid
down the area around the hole. Whith hole uppermost, slightly stretch over a finger
and any oozing snot will boil off, then rubber solution.
Converting £10 tyre to £30 one ?
Only an idea so far, as no reason to replace a tyre
yet. Set the tyre up on a geared down motor and pulley
to drive the tyre round and a couple of other pulleys
to keep it vertical. Extrude hot melt glue of a number
of sticks into a layer in the tyre , keeping molten with a
hot air gun on low setting. Eventually kill
the hot air while still turning the tyre.
Leaking Presta type screw down valve
Brand new but unused for a couple of years and
the central plunger was seized outwards, eventually
freeing this spindle , the seal must have broken or perished
inside.
Cut an inch piece of hot-melt glue stick (just because it
is deformable). Drilled a hole most way through axially
with a 3/16 drill. Force the stick over the valve whilst
"screwing" on and compress to the metal valve barrel
with a small (fully wrap-around ) jubilee/hose clip
Winter time cycle helmet use
Cut a piece of bubble wrap to fit inside to
cover the vent holes, rather than trying to squash
a titfer between skull and rimband.
Derailleur block removing tool
Proper 12 splined/fluted removal tool one size 23.2 mm between protrusions
and 21.6 between flutes.
Other size , corresponding measurements are 22.6 and 21mm
For this one starting with a 1/2 inch BSW bolt for the larger size.
Ground down on a bench grinder until 20.5mm across flats of the bolt head,
22.8mm across 'points' which were slightly ground back to clear.
Packed out the shank of the bolt with some washers to fill up
the recess in the block to localise better and screwed on nut
tightly. Hacksawed off the remaining thread except 2 threads and well hammered the
end of the bolt into the nut. Push bolt into block recesss so
6 of the 12 flutes are engaged and apply socket spanner to the nut
handle extended with tube to about wheel rim radius for enough foot-pounds torque.
Replacing a pedal that will not stay screwed into the crank because
the aluminium thread is stripped.
Removed pedal and took apart.
Incidently 11 off 4mm ball bearings each end of this pedal.
With bench grinder grind down the bulk of the metal where the pedal
spanner goes just leaving enough for a thin pedal spanner for purchase
and grind down to a diameter a bit less than the thread diameter.
Cut back part of the innermost end of the pedal to clear the crank
to give pedal spanner access. Screw in so that unused innermost section
of aluminium thread is engaged and because this one happened
to be right hand pedal screwed a small olive coloured nut off a small
military connector on the protruding innermost thread end.
For left side pedal presumably swage part of protruding thread
with a centre/pin punch to lock in place
Pedal is a half inch closer to centre but not noticable in use.
Bike chain link removal / remaking
Start the pin on a link moving with a link removing tool.
Knock through with a pin punch.
Reassembly check for right length of chain around the cogs
but before linking back remove tension by taking off the chainwheel.
Squash the pin just the thickness of the link with parallel jaw
pliers or engineer's clamp. Align both ends and pust home flush
with opposite side. Then lightly hammer until evenly protruding.
Hammer each side in turn with a large metal block on the other side.
File a notch on the link for future reference.
For Sigma/ Taya "tool less" chain link that refuses to slide
into its cup with human hand/finger force. Find 2 engineer's cramps.
Bend the closing link a bit, place over one pin
then a small washer to pad out and then a cramp across.
Then with a pin punch through the remaining hole in the link
lever against a nut or something , laying against the chain.
When shifted into place , remove cramp, twist the link to
line up over the other pin. Refix the cramp .
Squash the link over. Likewise with washer, squash the remaining link
but not too tight as not in the right position yet.
Using the cramps as handles, bend the chain to let the
remaining pin drop in position. Tighten the secoind cramp fully
and bend the chain the other way to force that end home in the slot.
Lay the cramps as near as you can get , along the chain ,
not across it.
Probably something wrong with the links, in a pack marked for
5 or 6 gear block , for a 5 cog block. But eventually a new
chain required. Both chains measured 7.4mm across any pin.
The new link pins measured 7.8mm and the troublesome/tight one measured
8mm, not 7.6 or 7.7mm which I could have expected
Another bike tip.
Useless shaft connecting cheapo rearview mirror to handlebar.
Don't know what the material property is but when twisted or
bent into correct position it would relax/creep out of alignment.
Consisted of 2 stout wires buried in molded plastic
which would not keep set position.
From a long wedge of wood, about 5 degree,left rough cut, saw
some inch long pieces and drill
holes in the middle of each section. Removed this plastic
spine and made a loop of bungie through the wedge bits
and around a screw retainer in the mirror end. Pulled
tight and knotted inside the mount around a bolt in
that area. Pack out with holed rubber washers to
tension up or cover with bands cut from a motorcycle
inner tube. Rotate the wedged bits individually to get the right angle and
rotate the mirror for the other angle. If knocked then
no damage and may even flip back into correct position.
A refinement is obtain a convex mirrror from
car bits "blind spot" mirror. Hacksaw off the mount
leaving the mirror secured in a rim of plastic
and hot-melt glue to the above frame after removing
the flat mirror. The ideal mirror would be flat
at the centre and convex periphery
Binatone answer machine , model 3900 from 1981
Not responding , no outgoing message
Probably due to distorted drive band on OGM
deck, deformed/perished? into a "V" at one point
so if stopped at that point
probably slipped. Changed all bands, cleaned relay
and manual function change switch contacts.
2 line phone line only
Bird Scarer
Scenario - soon after dawn every morning starlings
sqabbling and clog-dancing about the gutter and eaves -
an infernal racket, enough to wake the dead.
Found a pocket transistor radio and a small speaker.
Wired the speaker with long wires to a 3.5mm
earphone jack. Put a push switch in line with the
battery. Placed the speaker in the loft, directed
to the eaves and tuned the radio off station on the
medium wave to give a nice hiss.
Starlings promptly disappeared , telling their
mates "here be dragons" and found somewhere else to
stomp.
Bog flush system - retro-fitted 2 level.
After putting the bags of water in the cistern to reduce the amount
of flushing water. Then need an over-ride to let in more water
to flush 'big dumps'.
Seemed a neat idea for making a 2-level flush from an old simple flush
mechanism.
Pass a brass rod through the cuistern lid , located onto the ball of the
float valve.
Then add a weight to the brass to depress the float more, for more water,
until the excess weight is balanced off. Remove the weight for default cheap-skate
flush.
First requirement as a porcelain/ earthnware cistern , an 1/8 inch or so
hole in the porcelain of the bog cistern.
I've used a tile-hole cutter drill-bit on tiles before with no problems.
But on cistern porcelain got through the glaze ok but no further in than
about 1/8 inch deep.
I've not tried sharpening as it doesn't seem blunt and I've tried oil,
then, water as cutting medium but no further in.
I made a dam from blue-tac and made a crude drill bit from the shank of an
old HSS drill bit.
Grinding two flats on the shank end to make a sort of screwdriver blade.
Repeated sharpening 3 or 4 times.
With this got down to about 1/4 inch but then got concerned about breakout
on the inside.
This cover is hollow on the edges so presumably made by all angle rotation
of slip/paste
in a mould. I doubt if the central area is hollow though.
Tried firstly finding the internal matching point by putting some bits of
magnet
in the hole and tracing with iron filings but didn't work convincingly.
Then thought I'd try a Megger and presumably because of the dam
of water it gave a resistance trace so could find minimum position.
Could even use a 30 Meg ohm DVM as order 10 to 20 Meg ohms.
Found a small rod magnet and waving that about the outside hole gave
a very clear indication in the iron fillings on the inside.
With successively smaller "lollypop" grind stones in a hand drill
gradually zeroed in from the inside. Thickness about 10mm.
A tennis ball or 2 (if dislodged won't smash things) ,made a small hole and a cut
into it to load inside with
bits of lead. Glued a locator/protector to the ball valve to take the end of
the bit of brazing rod, must be long enough so is still located when
bottomed out and internal hole is conical so does not bind with
changing angle of the ball valve arm.
Cut a slot in a wooden wedge and for a refinement added
a 'crapometer' scale to the top surface of the wedge. Now just a
matter of working out a self return mechanism to the wedge to take it back
to the minimum flush setting.
Bog blockage
Flush water stops flushing away immediately, takes a
while to drop to normal trap level. Or
sometimes the water in the bottom of the bowl
disappears. Alright with just basin emptying ,
showers etc but if someone releases a bath
of water or heavy rain downpour feeds into
the system then the manhole overflows.
Probably a blockage at the outlet
, downstream , side of the first inspection
manhole. The manhole is filling and the waste pipe
is backing up to the bog so it can act as a syphon and draw water
out of the trap. Manhole full of crud. First make sure
you have a way of handling overflow of this crud
on the downhill surface level of this manhole.
Drop a garden hose down through the crud angled into
the anticipated direction of the outflow
pipe. Push down as far as will go and only then
turn on the water supply. Whether this clears the
blockage or not clean off the end of this pipe
before turning off the water supply to avoid
back syphonage. If not cleared then a more major problem
requiring rodding or digging etc.
Freeview digital tuner, loss of a channel, due
to some reclassification of channels at the transmitter.
Assuming generally enough signal strength
by checking on the "manual" tuning option
for the 6 or so digital channels for your area.
Switch off the box at the mains
Disconnect the aerial lead.
Power up and go through the installation process to clear
all contents of the stations.
reconnect the aerial
power on
Redo the installation process.
Broken plastic lever inside syphonic cistern.
That connects square shaft of the handle to copper
"S" hook that lifts the syphoning piston.
Rusting of a steel bolt had weakened
the wrap around the square shaft so it sheared there.
Find the stoutest of cable ties, and
tie tightly around the re-assembled lever.
Push bits of wedge from traditional sprung
clothes pegs into the mid sides until you can't
push any more in. Wrap small ties around
the ends so the main tie does not fall off
and envelop in hot melt glue to bind all
together. When back on the shaft locate in place
with a non-ferous washer each side and
stop movement with another small cable tie each side.
Incidently for poor flush function , this is the
way to make it work. If this fails then
replacement or something probably due to excess
water going up past the plunger rod rather than
up over the top of the syphon tube. Hold the handle at
its uppermost position for 2 seconds to depress
the plunger into the syphon chamber then pull
the handle down sharply and hold there until
syphonic action is definitely started.
After that, getting inside the cistern and bending the
float arm so the water level stops at a higher
level but below over-flow level of coarse.
Also relevant , if you want to save water consumption
by placing minigrip polythene bags of water in the cistern
then fair enough but don't bend the float arm to reduce the
height of water in the cistern as its the height,
not the volume, that controls the
syphoning action. If the lever occassionaly fails to
return to the normal position and the cistern-full
level is too high you can end up with a continuous
stream of water flowing into the pan. The critical
level is no higher than the "weir" of the
inverted U at the top of the syphon and of
course lower than the overflow outlet.
Checking the run/functioning of domestic sewer run.
Use blue dyed cistern loo block totally
disolved in a basin of water and tip down
a sink. Time from the start to seeing
it a manhole. Some timing for a 1890s built
sewer, slope not known. 1.5m vertical drop over
1.5m horizontal through kitchen sink trap and
narrow piping at various slopes and then 15m of sewer pipe run
was 1 minute 50 seconds for a sewer with no problems.
Bosch GSR12 cordless drill
Intermittent non function
Two torx screws holding the motor to the gearbox had loosened
and loaded the motor causing glazing of brushes and commutator.
To refix the loose screws the fibre reinforced end plate nearest the
motor on a part twist comes away from the rest of the gearbox (not
obvious from inspection).For anyone who has to reassemble the
gearbox,the sequence of sun/planet gears is from motor to chuck-3 medium
size cogs,3 smallest cogs ,4 largest cogs.The 2 steel dowel pins nearest
the chuck lie parallel to the commutator axis for reverse rotational locking .
Bosch PBS 60 belt sander, 2002
Grating noise and burning smell.
The main bearing was seized and the outer bearing anulus was rotating
and melting the plastic of the casing. No longer held in place because of
melting the drive pinion disengaged from the spur wheel.
Owner must have been sanding something
like formica giving fine plastic dust. Must have got into this double shrouded
24x9x7 mm bearing and also with fibrous/damp material blocked the airway leading
from belt to motor fan. Before pulling off the bearing
with a gear puller, measure the exact distance from end of helical pinion
back to this bearing as it sets the position of the armature.
Before heating/freezing on new one, pack between fan and final bearing position
with something of correct thickness, about 10mm.
Cover old bearing with some PTFE tape and place in the case half,
that was not melted, due to outward forces and melting of the other half housing.
Place some epoxy in the melted section, push 2 halves of case together
and hold together with rubber band until cured, leaving remade bearing housing.
Notes , no grease on the helical spur-wheel / helical pinion gearbox and
resistance on 240V version between L & N was about 13 ohms,
at least one of ther studs/holding nuts for the rubber belt pulleys are
left hand thread.
Black & Decker BD163C drill
Hammer action engaged in drill posistion
Ball race worn into the cam ring that you rotate
to select drill or hammer, so permanently engaged.
Comes apart easy enough, 2 short
screws near the chuck, make sure the chuck bearing section
has the flats positioned correctly to reposistion
in the housing on reassembly, add/move around
the grease before closing up
Remove the T/H lever and then cam ring and made up by cutting
and grinding an anulus from 0.35mm tinplate
30 and 22mm diameters , slightly larger than the
cam ring . Clamp to the rear of the ring and push the
tinplate into the recesses to make a crinkled washer
and place under the ring.
Now the hammer action would only engage when
pressing very hard, perhaps .25mm shim not .35mm
but no trace of hammer action when disengaged which
was the useage 90 percent of the time
Black and Decker GL320 strimmer
Intermittant stopping of motor a knock on the housing would start it again.
The brush housings are made of steel which had corroded.File back
corrosion and emery paper the sides of the brushes to allow free
movement of the brushes.To gain acces to motor requires removal
of the part circular cutter cover,undo the one underside screw (pack
with grease on reassembly) releasing the plastic peripheral catch and
rotating 1/4 of a turn.
Braun 5584/28 shaver.
Dropped on hard floor and ceased working.
A small bifurcated contact had sprung out of the burst case.
This was the main switch contact sheared off ,reset
in with hot-melt glue string.Couldn't sensibly repair the broken
anchor points of the cover but owner did not mind
a ring of 3 interconnected small cable ties tightened external
to the case
Braun Oral B electric toothbrush , 336 base marking
Sluggish motor
Looks 1.2V , ps 2.4V and motor runs far too fast. looks as though it was a
switch problem. Running 2 to 3 amps and start 3 to 5 amps. Switch is paired
up , to take current, pair of 1mm wide prism point contacts, one being
dirty. For same reason that powering the motor from 1.2V via a pair of
croc-ended leads drops far too much power.
It is surprisingly easy to remove the base "plug" 1/8 turn
with a steel rule on edge, then dart tip to get inside
these, and no wires to break, so worth a bit of time to repair.
Make an index mark to realign on assembly, 1/8 turn back to start.
Interesting , for those with mechanical bents, double crank and rubber mechanism creates
the motion.
Initially checking charger, with DVM Fluke 77 and 1mH small choke
measured 0.45V ac, 9 turns of wire around the location
spigot gave 0.1V ac, 0.6V when inside and the coil disconnected
and laid over the spigot,
no account made for HF not 50Hz.
Monitoring 1.2V nicad 1.24V drops to 1.16V in use.
-ve terminal to charger coil end. Coil 7.5R.
coil, thin O ring, paxolin ring then conical spring.
One motor terminal just for mounting purposes.
Good wodge of silicone grease on the active end before
fitting back in the casing.
Again, worth repeating, make a frame to hold any electric
toothbrush upside down , to dry off , before mounting back
on charger. Or preferably make a sliding yoke mount
under a shelf , with charger upsdide down, to
avoid spittle going into the works. Just because a
small condom like gaiter around the active end, so better than
rotation through, still can leak goo.
BT SGW 09UK 04 wallwart ps for answer machine (not seen)
leads pulled out of the modem/telephone plug
repaired as in tips files.
With the polarising clip upwards
R,Y,-,-,B,G
T-R DC, B-G AC
Cat Eye Halogen Hyper bike lamp
No light output
Nothing to do with the 555 for half brightness
setting.Due to rainwater ingress corroding one
of the contacts (not obvious inside plastic battery
housing) that connect the two outer batteries together.
CLI Add on for caller line indicator
Starting with a Binatone Clip 100 Caller Line Indicator
I wished to add a home-brew to audibly indicate when the
caller has "Withheld" his number and the "Unavailable" situation
so i don't even have to break away from whatever i'm doing to view the
display let alone lift the receiver for more junk.
Unavailable - usually foreign callers .
That is using the BT FSK toneburst that precedes the
fiirst ring pulses. These units decode the info and display
the caller's telephone number (if not disabled).
I now know I'm being plagued by random tele-sales
calls generated by computer. That is bastard systems dial
out multi-lines by computer and if anyone picks-up the receiver
the system switches to a sub-'human' for the sales-call.
If these bastards are all tied-up doing their speal then the line
goes dead when i pick it up. A growing problem in the UK
and presumably elsewhere as well.
I know i will lose a few genuine UK callers ,who for
whatever reason have disabled the ident of their phone ,but I consider
retaining my sanity of more importance. I've taken a
spare one of these CLI units apart and there are 36 finger
contacts to the multiplexed LCD display - lower row of 14 large digits
,an upper row of smaller digits for time,incrementing count ,date
and other annotations.
For display -WITHHELD- a uniquely identifying sitiuation is
3rd digit central horiz. bar present and
4th digit absence of top horiz. bar of the alphanumeric letter W
For display -UNAVAILABLE-
1st digit present central horiz. bar is unique
The microcontroller is epoxied over so inaccessible.
Driving the LCD from an af generator about 80Hz and
about 3V pk-pk square wave. Too high a voltage and
extra segments light, too high f and too feint and
too low f then flickers. Also for determination the lines 29 to 36
on the pcb show a different DVM "diode test" value ,
back to the micro ,to
ground, compared to the 1 to 28 lines (LCD disconnected).
The LCD has 8 back-planes,
(numbering on pcb) lines 29 to 36.
33 to 36 relate to the (9 and 2 half) small digits and legends
29 to 32 the 14 large digits
For first 3 large digits and segments a to g (a at top ,then
clockwise) and an extra
double vertical segment (h) giving central segment of W.
( The double segment 5h is angled to give the right hand V
segment of unaVailable and I of wIthheld as not full alphanumeric dispaly )
Control 'matrix' (for just lines 1 to 6 and 29 to 32 and digits 1 to 3)
**/1 ,2, 3, 4, 5, 6,
29/1d,1c,2d,2c,3d,3c
30/1e,1h,2e,2h,3e,3h
31/1b,1g,2b,2g,3b,3g
32/1f,1a,2f,2a,3f,3a
lines 7 to 28 for remaining digits 4 to 14
For the UK anyway (digits 1and 2 blank) digit 3 only shows 0 for first digit
of disclosed
numbers so segment 3g off , 3g on only for the first - of "-WITHHELD-" and
first 2 digits blank.
the 1g segment is always off except for the first - of "-UNAVAILABLE-"
As far as i can readup for multiplexed LCDs segments only 'light'
when the timed stepwise voltages between BP and segment
exceed some threshold
followed by the reverse phase of this voltage.Then relying on
persistence to maintain till the next cycle if still driven.
For all other smaller differences in drive voltages
they stay unlit. To avoid doing timing circuits would it be possible
to construct simple analogue differential amplifier
monitoring lines 31 and 2 for
'unavailable' and 31 and 6 for 'withheld'.?
Just one phase sense ,say BP greater than segment by 2.2V or whatever
(set on test),
and ignore the the reverse phase which is only there to keep
the liquid crystal happy, as far as i know.
Integrated outputs each gating one of 2 tones or patterns on a sounder,
heard between the rings of the phone.
On second thoughts i will choose 4h (pcb lines 30 and 8 ) as
the identifier of the vertical W segment
of WITHHELD (AND the 5h 'I' of 'withheld' ) ,
and 5h ( pcb lines 30 and 10) V of unaVailable
as i seem to remember,very rarely, some displayed
long mobile phone numbers use all 14 digits for the
number of the phone so a 2,3,4,5,6,8 or 9 there would
falsely register as withheld or unavailable.
Contrast is achieved by drive voltage, for 4V
battery supply
Contrast level 8 extreme output levels 0 to 4V
level 4 ,levels 1 to 4V
level 1,levels 1.6V to 4V
Eventually made just a cut down version.
Just decoded lines 10 and 30 to give a buzz for
unavailable and withheld situations only.
Both lines and battery connections to an external
box. Single rail quad op-amp, 10 and 30 lines to 2 window
comparators, integrator and piezo driver from Hex buffer pack.
The level shift pots may be problematic with
battery voltage drop.
Cyber Home ADL5 DVD player
or model AD-L528, 2 labels
from cold , a part second, partial feint display on the fluorescent, then
nothing.
All voltages agree with legends of 3.3,5,12,-20V dc and 4.4V ac to the
display. Standby voltage of 2.1V on switching power on.
RAT5V has 5V to the display/front controls board
with a PT6311 but no bus signals to it from the main board.
Main board main chip has a bonded heatsink over it,
Winbond 130 WG , CS4955 etc, but no activity on the board.
About 60 electrolytics and no IC protectors spied and likes of basic LM1458
have correct DC.
The heatsink will twist off the main chip quite easily.
Crystal CS98010CMEP
all electros check out
27MHz oscillation at the crystal oscillator and 5V is passed through the
gatekeeper KIA70 31AP and 3.3V rail is continuous to the Crystal chip
Standard linearised graphic logo of Crystal on the main chip
Tried disconnecting the deck. The owner seemed cagey , when I
asked about any precepitatory events.
I get the impression it is possible to download software fudges to disable
regionalisation etc. If the owner did this with some corrupted source could
that action have caused a hardware latch-up, or do manufacturer's
deliberately put a close-down function in there. ?
I can see there is a disc in the drive, but I've not dismantled to remove
it, (no mechanical functions, switch responses or display).
http://www.adl528.com/cyberhome/AD-L528---ALD5/index.htm
I wonder if it can be a software bug
That site mentions
"On occasion unit will power on with no life at all - no standby LED"
with no mention of a reason/solution.
If it means dead without even the unit's display lit and no Standby LED
then that is what is here but permanently.
I've tried the factory reset sequence mentioned there.
Further onto the main board I thought I'd found a SM inductor on a power
rail, blown as a fuse.
Legend L on the overlay but measured 1.2K ohm, but numbers over the
"inductor" itself said 122.
Yukon 77B Metal Detector, 1976
18V supply , with all 3 battery connectors seriesed
together there is not the 12V supply to the speaker
amp but a low level output for checking operation.
Search coils pin 1 common 2 5.8 ohm, 3 3 ohm, 4 4 ohm, 5 11.5 ohm
in crescent order
National Semiconductor 8 pin DIL custom? chips marked 274 0-004 and 624
0-001 I would be interested.
search coil 20V p-p "tone burst" of 12uS period
every 3.6mS for 1.4mS duration per cycle
Probably opamps
one marked 0-004 DC on pins 1 to 8
.8,4.4,3.6 1.5V tone burst,0 , .7,.6,9.5,9.5
with exponential sawtooth of .8V p-p
nearest markerd 0-001
7.6 neg going pulses,3.3, 3, 0 ,
6.6V 7V p-p square plus exponential, 3.6mS
6.6V 2V p-p near square,
6 7.5V p-p square, 9.5V
other 0-001
2.8,4.8,4.5,0 ,
5.4, 5.7, .6V exponential with pulse
positive 3V pulse
17.4V
Coin Magnum metal detector,1978
18V supply , with all 3 battery connectors seriesed
together there is not the 12V supply to the speaker
amp but a low level output for checking operation.
Search coils Gy-Or 19 ohm, Gt-Gn 121 ohm
Anyone know what the central lump covered in vacuum
moulded cover is hiding something active
pinning 1,2 on long side clockwise to 6
DVM measurements on desoldered lump
pins 1 to 5 29Kohm.
o/p coils 10V p-p ,70 KHz on
Gy lead with 2 phase "glitches"
0.2V on Green lead to 2V with metal.
Test pins I numbered 1 to 10 going clockwise
from top left
1 &2 &3 70K pulses, 4.5V
4 4.3 to 3.9 V on metal
5 3.8V to 2.6V
6 2V p-p rough sawtooth
7 5 to 6.6V
8 10V p-p
9 1.6V
10 7.6V t0 .7V on metal
C-Scope TR850D,1986 metal detector
Cannot be used in the rain without a cover
over the control bax and speaker.
Original speaker was 35R, replaced with 16R + 15R small W/W
Digital Camera close up lenses for basic camera
Temporally fix a lens over the camera lens
using rubber bands and gap padded out with
a large rubber grommet to avoid scratching.
3 dioptre spectacles lens over the front brought
focus to 16 inches
2 dioptre down to 11.5 inches
9 dioptre, or so, magnifying glass down to 4 inches
in front of the lens, requiring the making of
a "rostrum camera" mount for steadying.
From some aluminium bars cross-linked to
make an X , with spring washer on pivot bolt for
friction , 2 bars at right angle to 2 ends
to make feet, covered with heatshrink to
protect object. Then camera mounted via its
bottom screw point and shutter release
detailed elsewhere here, to avoid shake.
Dimplex FHS20 bathroom heater
Well i'm not proud. No output.
Built onto the frame of the heater element is
a small thermal cut-out with a black reset button. It had been
left switched on too long and did its job.
Dremmel Mod 358, ser 5-13, minidrill
I'd not noticed before but there is a lot of axial
movement of the chuck. Normal or worn ? Went inside , needed a clean out and
lubricating if nothing else. There is a wavy thin compression spring/washer
on the axle but it is about 1mm away from the bearing, so about 2mm of
possible movement between static and active use.
Someone else with a similar model had 0.5mm of play.
Mark which way round the bearing retaining clips are mounted and
the stator orientation before unclipping the bearings.
Note the stator wire furthest from the cable inlet goes under
the brush mount. a nylon pad is located as axle back stop.
The shaft is domed at the end and for some odd reason a pip on
top of that that had worn into the pad. Turned this pad around
and added 1mm extra padding glued behind it. But was too much
so removed and added 0.6mm instead. To check out motor and
using commutator bedding stone its a matter of
taping around the chuck lock spring ring and a couple of cable
ties around each brush mount and around 2 partially replaced body screw and through vent holes
to operate with the commutator exposed.
Triac BT24A, 100nF 250V, 10K,4.7K, 390K , 56R
and log pot that measured 220K max, in cct
Durabrand PSTB1 freeview receiver
If very low signal level on a few channels but
good level on the great majority. Try
placing the receive rin another position, including
vertical mounting.
Dyson DA 001 cyclone vacuum cleaner
I took pity on this m/c dumped and had been rained on, half a pint of water
in the lower casing.
I've seen a hose attached to these beasts but took me 5 minutes of head
scratching to discover that secret, as no external hose attachement point.
Powered for 2 seconds, sounded ok but probably too slow and an excessive chemically/
ozone smell. Then tipped upside down
to get in case and water flowed out but had not been enogh to invade the
motor. Needs Torx 10 and 15 drivers to remove casings.
Fancy looking design appearance but the motor to me looks like the same sort
of vacuum cleaner motor of 30 years ago, 1200 W.
Nothing visibly wrong with stator coils or rotor coils. Resistance
measurements across and between
segments seemed ok. Bit of a noise from the brushes once a revolution, spun
by hand.
Pulled off the spade terminals to unlock and then release the brush
housings. Then spinning the armature with a finger nail against the flow and
gradually increasing the nail angle
a point was reached where one armature segment would catch. Measuring with a
1 to 2 inch micrometer then
the diameter across the commutator was 1.185 inches and 1.192 for the errant
commutator contact strip.
Plenty of life left in the brushes but spark erroded surfaces and broken
leading brush edge.
Ground back brushes with bench grinder then a one inch
diameter cylinder grind stone to give approximate hollow
profile.
Inductance measurements on the commutator
wer 180mH per diameter and
2.9,1.6,.4,.4,1.6,2.9 mH ( 1000Hz ac test V ) for 3 contacts either side
of any given contact so no cold shorts anyway.
I couldn't see what physical mechanism could cause one land to be
7 thou (mil) proud of the others. Also while still in use, why the brushes
weren't ground down to nothing with that sort of irregularity.
Had localised heating caused the copper of that land to somehow permanently
expand by carbon incorporating into the copper or unstick from core and
restick perfecly aligned but proud ?
Centred to shaft in 4 jaw and turned down the commutator,
tieing back the motor frame. Found a piece of
tubing to sit on the chamfered fan end of shaft to localise
a centre cutting tool.
On checking for
bridges discovered there must be a break in one of the rotor coils.
Must have disturbed it in turning. Traced which coil and it connects
with the errant commutator segment. Found the loop nearest the
unseen break. Then scraping back a few loops and measuring found
one nearest the break - must have left a few turns but only surface
turns are available like this. 24 commutator segments 12 rotor coils.
Marked axially the 2 commutator segments 'in line' with the axial
parts of each coil - separated by 10 segments. Then the segments
connecting to this coil were 2 segments rearward on one side and
11 segments rearward on the other side.
Stator wires 0.028 inch diameter and rotor coil-wires 0.019 inch.
Gingerly pulled the best bared coil away from bulk, cleaned back
some more and soldered some 0.019 wire between
there and the relevant sement. Put som mica in place, varnished back in
place after fixing back this loose wire.
Gradually powered clamped to bench via 6Amp variac to about
50% mains to bed in brushes. Mounted back in housing with bottom
removed but motor held in with 2 large cable clips and spreader piece
of wood so start torque does not displace things. Continued bedding
in taking variac to 100% mains.
Ebac Humidifier 7, approx 1987
To remove back , remove 4 large and 2
small sdrews. For the front requires prizing
the bottom plastic from the wood surround
with a driver throug the glue from underside.
Siezed bearing/s on the Magnelek motor ser 1Ga ...
240V, .2A., 335R impedance protected 4 pole coil.
Need to flex a couple of the fan blades to remove.
Undo the fan nut and remove .
Then after releasing the 2 long bolts, bash
the spindle breaks the motor intop 2 parts
enough to clear gummed grease on spindle
ends and one cup to free up.
Seting of + and maximum on controls
When working the rime builds up on the outer
set of coils at the water drain end in about
2 minutes, then 45 minutes before the insulation
of the frost built up allows water to drip off,
for room temp of 16 C.
In first hour , after switching off and
collecting melted water , 150mL
Electra washing machine
Catastrophic flood
This machine so old the model number worn off.
The rotating stainless steel drum is housed inside a static
stove enamelled drum. This drum is secured to a ring holding
a lump of concrete and the front hatch rubber seal. A long term
leak had rusted the band that secures this static drum to the
concrete section and snapped. This band is U channel formed into
a large circle with closure/tightening made with a large nut and bolt.
A triangular section rubber band forms the seal inside this channel ring and the
flanges of the 2 drum sections. Spot welded a couple of curved inch
wide pieces of steel over the break to repair as a spare was not available
(far too old). Cleaned the rubber seal and other surfaces. The cut ends of the
rubber joined by a piece of studding pushed into the hollow
interior so it would hold together around the gap area. The following is
with hindsight the sequence to dis/reassemble. Remove the top pannel
and the front door. "screw" the opened out (like 1 turn of a helix)
U band through the front hatch way ending with open ends at the bottom rather
than as original at the top so the rough welded section is at the top where
not having to retain water.
Turn the m/c over onto the front face and disconnect the 4 large drum retaining
springs using an old large screwdriver with a small notch ground in the
active edge. Push the screwdriver through the spring and push on the end
of spring loop to disengage and later to reengage.Align rubber,U,and both
drum sections and tighten the U band bolt (not much tension is required to
form a water seal-the bolt anchors at the ends of the U were only spot welded) then reassemble.
An aside on washing machines:-as a short-term fix for sqealing/slipping
motor V belts dust the belt with French chalk as used by sweaty-handed
gymnasts to gain grip on rings and bars.
Electolux heater type (ammonia ?)old domestic fridge (3 foot high) .
Not exactly repair as it is still going after 40 years or so. Assuming replacement
heater would be obsolete the owner wanted me to measure the rating of the element.
So switched off for 10 minutes the resistance of the element was 66 ohms and when
plugged in (240 volt) still with the door open the continuous power use was 120 watts.
So probably all such fridges similar.
Flat roofing repair
For a bodging repair I can recommend hot-air gun, hot-melt glue and gun and
odd patches of felt.
The problem I had was failure of multilayer felt over a few felt-nails
and a partial split over an edge timber, so relatively
localised but has put off complete refelting, so far, for more than 3 years.
Clean affected area of stone, dirt etc, heat up with hot air gun in general
area around the problem and hot-melt glue around , then patch plus a bit
more hot air so all well fused but only the glue fully melted,
felt is just softened.
It is in full sun and no problem from sun-heating.
Hayterette lawn mower, ancient
Briggs and Stratton
92902 4stroke 3.5HP
It had not been used for some years after it had stopped working properly.
Changed the fuel and after starting would run for about 6 seconds
with no revs to speak of ,then die. Stripped down the carburettor and
reassembled and it works fine,i suspect it was mis-aligned compound
linkage between the throttle cable anchor rotating plate,the rotating plate
attached to the throttle butterfly and the governor arm (wind vane).
from: Bob Archambault
This automatic choke responds to "manifold" vacuum (i.e. vacuum on the engine
side of the throttle valve). Vacuum is routed thru a passgeway to a chamber on the
fuel tank (under the diaphragm) to pull the choke open against spring tension. It is
not temperature-related at all. When starting the engine, the choke remains mostly
closed because the throttle is open and the engine is not yet producing much vacuum.
After the engine starts and comes up to speed, vacuum increases and pulls the choke
open. If this results in a mixture that is too lean, the engine will begin to die out - which
will result in a reduction of vacuum, and the diaphragm spring will start to close the
choke. This will richen the mixture, and the engine will pick up speed again. A balance
is thus achieved. Soon after starting, the engine is sufficiently warm so the mixture with
a fully-open choke is perfect. However, when rapidly opening the throttle, the choke will
close momentarily due to the drop in vacuum, thereby briefly enriching the mixture. This is
similar in result to having an accelerator pump. The engine will speed up smoothly, without
tending to die out.
Champion CJ-8 plug and gap 28thou, no deep plug socket for this size
but with nipple removed could use a "3/4" inch socket shifted axially and the T bar got
just enough purchase.
Magneto HT coil 2.61K, 1.57H
Poor smokey running
Very dirty spark plug, cleaned with petrol, toothbrush and toothpicks
to get into the recess.
Broken start cord.
2 metres of replacement cord, not all required,
as dependendent on turns on the pulley. Not
too thin as will "upset" /jam in the pulley slot
if too thin.
Remove top cover, remove remnants of cord.
Find a bit of bar that will locate in the pulley
where the spline from the engine fits. Also a
ratchet socket for this bit of bar.
With the spring wound neatly in the retaining well
and the end located on the pulley and in
place in the cap. Wind the pulley anticlockwise
with bar and socket wrench. Until no more and
back off until the hole in the pulley and
lead out hole in the top cover are in
line and hold in place with a G-cramp, not too tight.
Pierce the cord 1/2 inch back from an end
to take the end of a piece of wire. Loop
the wire around the end of cord and lead out
6 inches or so. Introduce through pulley
and guide until knot seats into the pulley.
Release G cramp and let pulley
wind cord onto pulley, no further than
cord exceeding space in the pulley and
replace the handle.
Bad running, requiring the throttle to be nearly
fully open and eventually stopping with
sound of boiling petrol from the carburettor.
The spring between the end of Belden cable of throttle
quatrant arm and the small lever that goes inside the
engine block had weakened .
Hitachi HMP 505 microphone
Broken on/off switch.
Remove on/off label to access screws. Undo XLR
connector screw.
Unscrew mesh and desolder 2 wires and solder to a piece
of wire to pull back through the hole , so can pull back
the replacement
Honeywell S4565CF 1029 boiler controller
Gas fitter had wrong meter range when testing why
gas valve not working.
He knocked out the 100R,1W dropper resistor, giving about 80V
rectified ac on a DVM (ie no load), should be
about 230V "dc", rectifiers were ok.
Original problem was intermittant
failure of controller, due to poor solder leading
to break at the 24V relay that supplies
the HT to the solenoid circuit and flue fan
Uses spark generator coil 1300 ohm, .34H and about 0.2R
DT149c, LM33?, SI1 V120
18V relay hold/reset ?
Access, turn up long flap on the red part
of housing under header pins, the grey section around
the flame sensor and spark generator
connectors slides out from the rest
of the grey housing after turning back the plastic lock-tab.
Infocus X2 image projector , 2004
Prior to that , not seen by me , only reported, there was a slightly
diagonal shadow across the very right hand edge of the screen, but still
being used like that.
The whole inside is covered in dust, including a very dusty reflector on the
bulb.
The actual lamp is marked SHP58 Hg.
Discovered what the original problem was.
A rectangular tunnel between the colour wheel and the first lens, going
across the airpath of a fan. Made of silvered microscope slide glass , 4
pieces forming a rectangular tunnel about 30mm long 4 x 3.7mm internal bore
but the glue at the
corners failed with time or heat and the retaining spring pushes one edge in
a bit. With no silvering it would have absorbed more heat and probaly
rapidly failed. The mask , part of the clamp, was seriously black,
required grinding off, oven cleaner didn't touch the burnt on nicotine
tar or whatever.
Removing the spring and the tunnel collapsed, i'm surprised the fan air
didn't totally disloge them. If rebuilt, bend the vertical part of
the spring away so only held by the top should avoid similar movement.
I ditched them totally and replaced with some 0.4mm polished stainless
steel bend around into a square of 6mm outside dimension. Not
closed on the closure line, as my original fracture trying to close round.
Added 1mm of PTFE sheet on the bedding plane furthest from fan
and 0.5mm on the other plane as packing. For normal table-top
viewing id a shadow on the RH edge then obscuration of the light tunnel
at teh edge nearest the fan.
Putting a 50 watt floodlight mercury discharge lamp across the feed, either
way round produces nothing.
Putting a 110V neon across the feed there is a constant orange glow but no
initial flare - too short to be seen ?.
Putting a 150 watt spotlight discharge lamp there, nothing.
Even tried a 9 inch standard fluourescent tube in all orientations.
I've removed the ps board. The high power, LV, side of the lamp drive looks
ok, despite some varnish browning around some wide format 1K SM resistors.
But on the assumed HV section, the inverter size and type of hf transformer
measures weird.
4 segments to the wiring , 1 thick wire and 3 fine wire all the same fine
gauge, secondary coil 115 ohm,80mH, 0.22 mm primary wire.
11x11x11mm bobbin.
2 pairs of SM 1K R on LV circuit and 2 seriesed 2.2K droppers on HV cct
No 12V is getting to the HV circuit of JRC 2901 quad
comparator/transistors/inverter transformer, because the Q501 B764 pass
transistor is held off by an isolated line from the video board. Taking the
output of the opto isolator low by 330R the HV circuit works.
I now know that a standard 50W floodlight mercury discharge lamp will work
on this circuit as will a 9 inch fluourescent tube and more diagnostically
380V neon runs fine but nothing without the HV circuit, 110 V very bright
and a low output without the HV , just the 62V power sustain voltage.
Main ps heatsink about -150V to ground, lamp o/p
approx 320 to 380V. ps board has a black standoff clip at centre.
inverter transformer 2 sets of 9 turns and 2 turns for feedback
2x D1865 for drive
7812A, K2917,K2647, 28061, K3568
100K, therm 18R NTC, 2x 0.47R, 2x 0.16R, therm 6.2R
th sw 100C ? Asahi US-602H / 100CH
LED color/behaviour
solid green
The power switch has been toggled on
and the software has initialized or the pro-
jector has been powered off via the
remote.
blinking green
The power switch has been toggled on
and the software is initializing, or the pro-
jector is powering down and the fans are
running to cool the lamp.
blinking red
If the projector has been working but
exceeded its lamp life , reset the lamp hours by simultaneously pressing both
Volume buttons on the keypad and holding them for 10 seconds
solid red, An unidentifiable error. Lamp hours is just the in-use time
from last reset, not a function of lamp "wear".
2B47 IR receiver and amp pinning 3.3V,0,o/p
Osram Halopar 20, 68832 FL could supply the 60 mm
reflector. Remove front UV-block glass, held on only with
RTV silicone probably, and bass brass, burr out
the indents then tear away the brass. Try the 50 Watt
lamp set further back or try a short 150W 240V linear
floodlight lamp set in fire cement . Run off the mains via a
relay driven from the fan supply, Remember 2 types
of fire cement, try different positions with non setting
and finally use setting type. Water-glass maybe useful as well.
Had to grind away the ends of a mercury discharge lamps , wire
in and cover the rearward extension with a cover bolted
to the outside of the projector made of lamp fitting and Bulgin connector
high temperature plastic.
Results for this lamp , probably much like
the original in function . 300W overall consumption and 80V, 1.8 amp
lamp consumption, 145W sounds about right.
11,600 lux measuring with probe in the output from the lens. 50mm from the ring,
with no video and white "blank" screen . With A4 sheet illuminated and a photographic
light level meter, set for 100 ASA gave f4, 1/60 second reading. With ambient
of 17 deg C.
Using diode temperature probes, the parabolic reflector reached 85 deg C and 88 degree
after switch off. The light tunnel reached 46 deg C. The housing
between thermal switch and over the colourwheel reached 26 deg C
and 47 deg C at switch off.
Normal power use when warmed up 80V, 1.8 amp (measured with 0.1R
in line and hookup wire volts-drop). At first striking then drops to about 20V then increases
to 80V. If still hot when trying to power up
then starts at 1300 volts, drops to 64V with no lamp ,
470V down to 64V etc
until the fans have cooled it down enough.
Menu brightness change makes no
difference to lamp brightness. Changing to low power
setting does drop the light output, but volts
stay at 80 V so presumably current drops, used for lower
fan noise, very large screen display not required.
Blue screen , no signal, low power setting, with thermometer bulb placed
at lower left front where most heat is blown out took 10 minutes
to stabilise at 25 deg C over ambient.
Interplak Electric Toothbrush (Interplaque)
Intermittant loss of the charging light but no loss of battery charge.
The problem ,would seem to have been a defective SM LED. In the process checking
for possible
switch mode supply problems monitored the output but consistent OK. Used a
33uH "1/3 Watt size" (if it was a carbon resistor) choke as a pick-up connected
to a scope. At maximum
coupling the induced voltage was 50KHz and about 0.4Volt. Using a standard DVM on
AC volts range the maximum apparent signal was about 0.1V on the display. Maximum
coupling curiously was with the choke at a 30 degree angle vertically to the base coil.
Major components in the toothbrush a tabbed power handling devce and a 4060
presumably for the timer. The 2 halves separate by a twist and pull apart
The replaceable head converts rotary to reciprocating linear motion.At the
active end is two racks that engage with 2 metal cogs. These drive 2 separate
trains of plastic cogs. To gain access push small screwdriver into the
small hole at the furthest end.
A whippy noise from the replacable head along with slowing
to stall is due to a problem in the reciprocatory mechanism. Swap
the mechanism from another head where the brushes are worn out.
Another mechanical problem in the rotary to reciprocal conversion section of
the replacement head.
Gain access at the large end ,unclip inwards the 2 internal flaps in the recess,
then the only way to avoid awkward damage seems to be on the flattish side
drill a small hole 12mm down from the driven end lip,poke a screwdriver in
and lever off the closure . Glue over hole afterwards.
Part of a soft plastic that almost looks like wax often buckles or breaks.
Remove this nasty plastic. Bits required flat pin idealy crimp Varelco hermaphroditic
the rivet part of a plastic snap rivet and matrix board pin. Cut off the insulation crimp part at
one end of the pin and both flat ends just beyond the "crack stop" hole
at the contact end. Flatten back the angled hold finger and cut off the
2 tiny fingers either side of the flat. Slightly widen the U of the crimp point.
Cut back the head of the plastic rivet down to just the central area. Mount rivet shaft in the
crimp section and crimp closed. Cut away indruding parts in the axial slot
wherer the "waxy" plastic was and slide into this slot. The rivet is because
you don't want the plastic of the oval section rubbing against metal. Drill a small hole
through the "crack stop" into the core between the X spline shaft and
the rotary section. Push a "matrix board" thru-board pin into the hole and solder
to the Varelco pin. Check nothing fouls the motion and reassemble with
plenty of food grade silicon grease. Make sure the part rotating
around the rack part does not bind when mounted back in the housing.
I can only assume the manufacturer doesn't
make such a modification is they want a "weak link" to fail to sell more brush heads.
After all even if stalled the motor does not come to grief ,for short periods anyway.
Rattly noise ,slower action and frequent cut-out
probably due to over-current monitoring cut-out.
Due to toothpaste accretion in the 'sun and planets'
reduction gearbox. Desolder motor and batter contacts,
bend back tinplate nibs, the gearbox just prizes off
the front of the motor. Cleaned out thoroughly with meths
and coated liberally with food grade silicone grease.
The sun and planet gearbox is 6:1 reduction (1 + 45/9 )clockwise
to clockwise rotation, sun of 9 teeth,planets of 18 and
ring gear of 45 teeth. If wear on the 3 planet gear axles
then pack out with some turns of cut-down plumber's PTFE.
Also for anyone who finds the replacement toothbrushes only last 3 weeks
rather than 3 months (as per maker's instructions) before tufts
bend excessively wrap around themselves and slow the motor.
Solution to stiffen up (preferably while still new)
each longer tuft at the driven end enough to stop them flexing so much.
Push back the "clip" to release the head containing the brushes. Need
something like those annoying coloured plastic rings pushed onto peg
board, then melted, for kids toy 'mosaics' ( Trade nameHama Beads ) about 5mm long and 5mm diameter. Cut
axially and wrap around the base of each long tuft after soaking in
epoxy glue. When cured "fettle the sprew" with a razor blade and reassemble.
Alternatively with 150 degree C soldering iron melt the bristles together
near the cog end. Then wrap folded plummers PTFE tape around this
now reduced diameter section and sort of heat seal with 350 deg C
soldering iron. The PTFE in a sense shrink wraps to grip.
Also use to pack out when the white
plastic housing gets worn down. To reassemble place tufts back in
cover and place loosely over the drive section. With a needle jiggle
the cogs to drop into the holes before pushing the cover home.
Water getting into the control area and gunge collecting under the click switch.
Open up and clean away all gunge,the click part of the switch is only hooked under the
pcb. Thence the following tip
Fault symptom - intermittant starting when sitting on charger or failing to
switch on or failing to switch off finally.
Preventative action for owners of electric tothbrushes. (ALL ELECTRIC TOOTHBRUSHES)
It is asking too much of these toothbrushes to have a rotating spindle through a
seal that should stop watery goo seeping through when the unit is placed
on the charging base.
Invert the charger base and fix to the underside of a shelf or
cupboard. Make up a fork to engage with the shoulder of the brush to hold
in place upside down. Or make a shoe to slide the brush end in supporting
the whole motor and brush up into the charger.
Any liquid then drains away from the electronics area.
JVC AA-V5 Power adaptor
No charging current
o/c thermal fuse TF2,115 degree C
In normal use .3W of heat from the
.2 ohm resistor seems a bit excessive
when insulated with a woven glass
sleeve so replaced fuse in thermal
connection with resistor but anchored the free end
of the
assembly with "ceramic" fire cement
K'A'RCHER 510 pressure washer
Foot switch not switching off.
The mains switch is probably not man enough for
a foot switch. The 2 part switch casing can flex and allow
one of the internal springs to dislodge and fail to return
the switch shaft to off postion. Also includes a thermal
over-current cut-out. Reassembled and placed
back in the outer plastic cover/holder and tightened
a 10mm cable tie around central area to beef-up.
KEF concerto tweeter problem, 1960s
due to crossover failure, DN12?, Sp1004 ?. Probing with a
dvm on ac range , no signal at the midpoint between the
two , 6uF, 50V non-polarised caps.
Actually the input connected one failed o/c, replaced both
with a 4.7uF, 100V polyester cap
Kenwood CJ66SS microwave oven, 2006
Owner put too heavy an item in the oven and the rotary drive made horrible
loud regular clatter noise after that, but cooker works still. On receiving
it was still making loud click noise of about 2 per second, very loud
disturbing noise. Security Torx screws (see tips files). By the time I'd taken it all apart and testing the
synchronous motor and 4 rev / min gear train, on mains , all apparently
working order. Turns anticlockwise.
After the pallaver of getting the casing off the oven , Torx security screws
etc. I now realise the well on the base deliberately has 8 weak points, you
can cut and turn around the punch out, and refix with a screw as a removable
access panel. Before removing base , as one hinge needs removing,
hold door closed with bungee and then refix hinge after removing base.
To remove top cover slide rearwards to release top and side ledges.
Decided on PTFE washer and tightening up output spindle bearing surface as
probably worn down. Squashed 1/2 the ring of surround metal opposite
the drive cog with mole-grips and fared off high points with needle file.
Reassembles and after a second much the same noise.
Probably misdirected by the owner it was loose mains primary
wire on the transformer. He'd turned upside down to
try and get to the platter motor and must have coincidently
dislodged the wire. A wash on the priomary side of laquer.
While in their 7.1amp primary consump[tion at 240V , 0.9A/5KV
secondary fuse , 1.15uF cap, diode RG606 CL01-12
"topband" pcb uses 20R and 2x 200R
Laser Scout metal detector, about 2002
Motion dependent detection - no beeping if head is static
over metal.
Dust on the diverter contact on the 1/4 inch jack socket meaning the
internal speaker output was cutting out.
It looks as though the intermittant non working was due to being used in a
field with a lot of very fine red dust blowing about, everything inside was
coated with it. Removed pots and switches and cleaned up and then blocked
holes in the case. Presumably wind blowing over the control box
created positive pressure on one face and negative on the
other making a nice air pump.
Using this or a similar machine when
headphones aren't plugged in, to plug a small rubber bung (tied on a bit of lacing cord) in
the socket hole.
Also glue some light compressible rubber cord on the ledge under the front
panel as dust or rain. Form a ledge around the curved section
with hot melt glue moulded by replacing cover
and then adding more melt when cooled/shaped. And block up the
3 holes around the battery cover
by squashing plasticine in the holes from outside and then dribbling
hot-melt glue over it, on the inside.
This is a VLF motion discriminator design (Tesoro) probably
circuit much like a SM cut down versiuon of the Elektor Nov 1981
circuit as uses 4024 and 4016 but not 4046s. Has +5 dc-dc converter
18AE,2931A,M-5.0 and somewhere a -4V source maybe the 22621,18T,A72J
although power pinning as the dual op-amps LM358M and LM393 and 4558.
Laser Scout metal detector
Dead machine.
Headphone lead had been wrenched presumably so
plastic bush of socked was part broken and
the innermost switched element was loose
after the plastic retaining lug of the socket
was cracked.
Lucas K2F magneto coil rewind
http://www.diversed.fsnet.co.uk//K2F.jpg
laying on cm/mm graph paper.
Orangey section is the laquered coil.
C area is the contact patch (supplying 2 HT leads in turn) moulded into the
surrounding paxolin? insulation, continued out to the boss marked P, but
otherwise looking like the tarnished brass sections in colour , marked B.
The curve above the C is the shape of one end of this contact section, not a
trick of the light.
A is aluminium housing for the contact breaker
As received by me, the secondary measured 22K ohm, now reads 6.3K , at this
stage, presumably shorted turns rather than a break for this one.
Every time I touch this armature the secondary ohms varies, 45K and 27K on
the last 2 occasions, so at least cannot make matters worse.
I can now see how to remove the coil assembly but not how that leadout is
connected into the paxolin drum. I can see me using glass tape being used
instead of cloth for outer protection, for anti-hygroscopic reasons.
From the Lucas pdf , under fig 6
http://www.bolsover.com/lucas/sectionL5partA.pdf
"Fit the new slip ring moulding on the shaft, taking care that the wire
enters the hole in the slip ring boss , and that it goes fully home without
bending. Seal the wire into the bosss with varnish"
Sounds a bit odd and don't know what it means yet, pushfit and varnish?.
The contact breaker housing comes off by slackening the central holding bolt
a bit and lightly tapping the bolt head to release a keyed bushing.
The capacitor, sorry, condenser measures 0.36uF which is presumably about
right value but as resistance was about 400K then no use for anything.
To remove the condenser as US and avoid use of a large soldering
iron. Thin screwdriver wedge action oart the hold-down
arm from the capacitor and similarly break
the hold on the screws.
A matter of removing the ballrace and underlying steel rings
and spacer from the brass section marked BR on
http://www.diversed.fsnet.co.uk//K2F_b.jpg
requiring making up an extractor as standard pullers have no ledge to
purchase on. Some soft iron rod formed into a ring
and let into the groove of the bearing surface. Mole-grips
gripping that diametrically and wedges and padding
under the pivot section of the molegrips,
shifted that sleeve off. HT lead emerges between the non-diagonal
pair of locating pins opposite
side to the thru' hole in the steel pole pieces for the wire
connecting to the points.
The 2 long screws go the length of the steel pieces like an electric drill
housing. Marked the orientation before removing the end cap. Yes the HT wire
marked W just pushes into the boss of the paxolin pulley shown in the third
pic. An excellent site for damp ingress , via capillary action, into the
body of the coil (my excavations exploring how deep the cloth covering was).
Green corrosion on the HT wire is more obvious in the original high
resolution pic, evidencing dampness at the end of the HT sleeving.
http://www.diversed.fsnet.co.uk//K2F_c.jpg
the capacitor is the square lump covered in greasy mess in the end cap
http://www.diversed.fsnet.co.uk//K2F_d.jpg
the paxolin pulley-like section that goes on the brass axis at W position.
Before excavating further decided to take a pic of the now obvious ingress
of damp down the HT wire. Lovely green copper carbonate staining.
http://www.diversed.fsnet.co.uk//K2F_e.jpg
net/diverse:graffiti.net/K2F_c.jpg
and the other cap interior where the contact breaker connection is from the
centre fixing , insulated under and around , by what looks like a black RF
coil former. Release the axial bolt a bit and tap
to free that section. The locating pins ,
2 diafgonal ones for the condenser end and 2
to one side for the HT bobbin end.
http://www.diversed.fsnet.co.uk//K2F_f.jpg
Unwinding and counting off the secondary under a
low setting hot air gun. The break was near the
outer end and 4 layers, 751 turns in the ohmage was 5.12K
so for 45SWG and 3.9 ohm/yd then full secondary
should be about 5.5K , 1417 yards, 1.61 oz
Primary about 171 turns as 3x37 and 2x30.
Check the metal sections go back in place without gaps,
before winding. Enginner blue the steel ends before squashing on the
brass ends , to find any high points and then grind down.
If you take apart the contact breaker, as I did, not realising
you just unscrew the central bolt/conductor. Its no good
fixing the other adjustment screw in mid-position
for checking out. You have to align the HT segment
of the bobbin with the cam at point of opening with the
the contacts actually opening.
Just a 3 inch piece of wood bolted to the tapered
drive shaft and turning by finger at about 1 rev /
second should show sparks on the plugs. To test
before reassembly just a 1.2V nicad touched between
ground and capacitor line, or when assembled
put some card in the contact gap and do the same.
some other useful info
http:/www.brufnut.de/WORKSHOP/LUCAS/lucas.htm
Before inserting the armature, checked magnetism.
2.5 inch long, 1.5mm diameter sewing needle on thread.
Grabbed by the magnet on one side, through
the Al, 2.5 inches away and 3 inches on the othe rside.
With a 1.2V nicad checked for spark , no cap required ,
then with a small neon 100Meg resistance was fine but 300M was poor
After fully installing and turning around by hand 500M fine but 400M
was poor discharge.
Lucas 1930s "King of the Road" bike light.
Conversion to insulated electrics so it could be used with a dyno-hub.
The top on/off switch has a brass spindle that passes and touches through
the casing and so the switch contacts are in electrical contact with the casing.
Open out the bush housing in the casing so some PTFE tape can be wrapped
around the switch spindle. Incidently why the small red lens on port/left side of the
casing and green on starboard/right side.
Magnifying lamp
Anglepoise/Luxo type with 5 inch lens and 8 inch fluourescent lamp.
Long term problem of the lamp clips dislodging and immediate problem of
the lens falling out. Anular tube held in place by 3 copper strips sprung
into the top cover but they work loose. Replaced with bits of 10 inch cable ties,
curled round and heated on low setting of hot air gun . Wedged and glued into the housing.
Uncurl the tie to replace the lamp. One of the 2 plastic lens retaining lugs had broken .
Replaced with large plastic cable clip for 1/2 inch cable. Squash the "free" part of
the clip with parallel jaw pliers and heat to soften with low heat setting hot air gun
forming an angled flap .
Remove the fixing nail and screw up into this hole through a hole in the lamp cover
and for good measure glue in place.
Anglepoise/ Luxo inspection lamp problem
Heavy glass lens, circular fluorescent lamp etc on 2 off 18 inch long sets
of arms with springs. However much you tighten up the central clamp the top
arm sags down in use, especially when you rotate the whole lamp or the angle
of the head.
Place a dense rubber tap washer under the nut of this clamp. Changing the
angle of the arms is then stiffer but I prefer that, to sagging in use.
In effect stretching the springs a bit, I chopped off a
bit of 12 mm hard/high temp hotmelt glue stick and cable-tied in place, a
tie around a loop of each spring. Pen barrel was not big enough.
All that agro over the years, just for the want of 1.5 inches of hotmelt
glue stick, 2 cable ties and a tap washer. It now lives up to the name
anglepoise.
Mains wiring problem
Main 5 amp lighting fuse blew not associated with bulb failure.
Replacement fuse wire also blew.
Isolating the mains there was something like 16Kohms , slightly
varying, between Live and Neutral. How to trace where the bridge/problem
was, single handed.? Connected one side of one of the dual pots of a
basic Wien bridge test gear oscillator out to the wiring in parallel.
Fed the oscillator output to a ghetto blaster and started tugging at the
wires entering each of the ceiling roses until pitch change. Found one line and
repeated in the loft, found to be squirrel had gnawed through to the
live wire but had lived to move elsewhere.
A One for All URC 3445 universal remote control almost full fix
Will do almost all on-screen menu functions as well
as transport functions, but
No explicit "OK" or "Select" button on this remote, the Mute button at the
centre of the 4 arrow keys is supposed to double as OK according to the
instructions.
This button works in TV mode as mute etc but no send LED when pushed in VCR
mode. For a Goodmans VN9500 vcr anyway, don't know if a genearal problem/fix.
In close succession to pressing Menu or arrow keys it will function as "OK".
So its possible to change preset channels, set clock etc by letting the
selection stand and closing the menu down back to normal function.
eg to change modulator RF out channel it is a matter of pushing in rapid
succession Menu/Down/Down/Mute/Down/Mute to get to the relevant selection ,
press 33 for channel 33 and then exit by pressing Menu.
But in timed/programmme record setting
it is necessary to go back to a previous menu to store and Mute will not
function then, exiting Menu directly loses the values. Anyone any ideas ?
Panasonic KX-T3716 cordless phone.
Intermittant failure of handset.
Replace the worn membrane type push to talk switch
with a standard small click switch,Remove 2 of the
four pins (diagonally) and solder in diagonally to
match centres with the key pad button.
Plasma Sphere, no makers name, 2000
Glass sphere on truncated black plastic pyramid with
12V (1A ac ) socket, Lo-Hi pot, on/off switch.
Intermittant failure.
To open remove slider knob, remove 4 screws, open enough
to prize on/off knob off (in on position) , pull LOPT wire out of double
sphere interconnect tube.
Uses 555, TIP122 driver and electret to peak to Hi
setting when pot set to a lower level.
FR157 (high speed 1.5A, 1KV diode connected to the LOPT )
heated sufficiently to char pcb and desolder
pcb connections. Extended the diode on pin pillars
away from the board.
Powakaddy 2 Golfing powered trolley.
No speed control.
Replaced all 5 paralled powerFETs BUZ71 and
added across the motor not in original design) a back-emf
protection diode for the FETs.
PowaKaddy Classic golf club trolley.
No function just a slight buzz from the control box.
Failed TIC126 thyristor,no gate function. The IRFZ48N
mosfet was OK.Remounted the PCB and Ali heatsink with
2 bolts and captive nuts rather than as original pop
(blind ) rivets.
Praktica MTL3 35mm camera
Not a repair job - was after a pentaprism
How to dismantle and may be similar to other cameras
To remove the top section
Remove the four obvious screws.
Force out the thin spring plate of the hot shoe
to expose 3 screws.
Remove central disc on lever winder and undo
the 2 internal securers
Remove disc with shutter speeds around it
and undo the 2 internal securers.
Cassette release pull and undo the exposed bush nut.
Proaction BH fitness bike , infiniti, Chang Yow
Nothing on LCD, bad rivet on battery connector midway contact
plus corrosion problem on a solder joint.
Pump up garden type pressure spray.
Perished rubber parts.
1/ the non-return valve that is under the liquid.
Cut some bicycle innertube rubber. If too large a diameter
, fold 2 or 3 times until small enough.
The cup shaped rubber on the piston.
Assuming you can find a tap washer of the right
diameter. With Dremmel and 1/8 inch ball mill mill
out a ring , leaving as narrow a wall as you dare to form
the rim. Then also mill away the external shoulder
of where this rim meets the main disc so the rim will flex
out of the way on the return stroke.
Remote Control car
Mechanical damage to front suspension after banging into wall
Bonded the cantilever suspension arm back to the chassis
with hot melt "soldering" (see tips files) melted under and around reinforcement
all round with aluminium expanded mesh (from car spares shops
for GRP patching to car bodies(multi-sliitted aluminium sheet
that is then stretched to form a grid of rhombic holes)
Response 200 answer machine 1993
Failure to recognise active phone line.
Should show alternately "HO" or "00" on pressing one of the buttons , just
beeps and 2 character
display stays at "o" and no activation to ring pulses.
Phone and tape sections working order.I'm assuming for the moment that the relay that connects
the standing DC on the phone line through to the other side
should be active when there is power to the machine and
switched to answer machine mode and active phone line
is connected so it can register an active line.
This relay and driver works if i drive it but 0 level on the only line
that connects back to the main micro so presumably an output.
The keyboard controller is signalling this main micro
when changing operational status but no drive to the relay.
Pins 21 and 39 on the TMP47c micro have signals
from keyboard but no output change.
Failed to discover the other control function or whatever
causing the problem.
Rewinding a petrol motor magneto coil.
Unlikely you will be able to count-off the number of turns on the old coil.
At least get an idea of the weight of secondary wire and an accurate
measurement of the SWG.
Also try and count the number of turns on one layer and count the number of
layers.
The one i rewound had a charred area buried in the centre of the secondary
windings.
After setting up the coil winder for a traverse rate that was at the bottom
of the scale and back-tension by fingers because that was below the bottom setting on the
winder.
For the actual winding it took only about 3/4 hour to do 24,000 turns if i
remember correctly.
And that included some paper salvaged from a high voltage electrolytic to go
over each winding-run before traversing back the other way.
For inter-layer insulation I just unwound a old type
valve/tube electrolytic capacitor 600V or so rating. Strip away
the aluminium foil to leave the shellac?ed paper.
After rewinding and before sealing, place in a low oven to make sure there
is no water vapour trapped inside.
Replacing domestic tap washer.
Or rather getting to the stage where you can replace a washer.
First run off some water in a container for a cup of tea &
hand washing. Switch off the boiler so no chance of
coming on with no water in the cylinder.
Turn off the mains under sink or wherever, preferably
than at the company mains point outside as any stuck then
fractured stop-cock there would be expensive to sort out.
Run all water out of all taps to drain hot tank and header
tank, assuming the problem tap is a hot tap.
Put plug in basin to catch any odd
grub screw or similar and protect porcelain
with old towels in case of dropped hammer or spanner.
For traditional cross handle tap with shaft it should not
be necessary to remove the small screw that holds
the handle to the shaft - just as well as is small brass and easily
fouled up.
Two types of covers one with a shaft that a cover slides
up and down on or type where cover is the handle as well.
With second type undo as normal and then try undoing
the collar that hides the guts of the tap. Assuming
this is not finger tight wrap a nylon cable tie around the collar
'teeth' inwards to protect the finnish and wrench off with small
'Stilsons' acting over the nylon of the cable tie.
Older traditional type - slacken the cover in same manner.
If a large amount of force is required then it is important
to balance off this force the other way by holding back the
body of the tap. More likely required in the following.
Removing the main section of the tap. Assuming
you can now get a 7/16 Whitworth spanner or
whatever under the cover. To apply balancing
torque to prevent 'collateral damage' to joints
etc in the pipework / tap-joint use a long T bar
box spanner large enough to go over spout and
similar length as the spanner ( or piece of piping with
a hole drilled in it at same length as the spanner).
Protect the finnish by sliding
some bicycle inner tube over the spout first.
If hand force is not enogh then make a Spannish windlass.
Through the T bar hole and the other end of the
open ended spanner pass about 5 turns of stout
string and tie tightly. Tie back the spanner to the
body of the tap in case it decides to move off the nut.
Use some safety spectacles yourself just in case.
Don't have your fingers in the gap beween
spanner and box spanner.
With a long shaft screwdriver pass through the loops
of string and wind up the tension, anchor off by
sliding up the screwdriver shaft and tie it off
just in case.
Then again using back force to counter the blows
whack the spanner with a mallet. For some odd
reason ( type of shock waves or something ) heavy blow
from wood on steel rather than steel on steel is
better at shifting metal on metal bound threads.
If that doesn't work then I suppose its a matter
of heating up with a hot air gun around the seized thread
then Spannish Winlass - not had to try that so far.
Undo small nut holding down the worn washer by
gripping the metal disc part in 'Mole Grips '
or prize off around the central pip if that type. Feel / inspect
the seating for any scoring as this could be the
reason for drips, if scored then acquire a re-seating tool.
One of those tools with some superb understated design.
A conical outer thread that will engage enough to localise
with any tap size. But mainly the choice of the thread that
the middle and outer sections engage. That is pitch and
form just right so that as the back torque releases from
the central rotating cutting section the middle segment
turns of its own accord top take up the slack - I suppose
some, anonymous to history, millright or similar dreamt
up such a self-adjusting mechanism.
Should the tap at closure have a 'hard' action at point of
closure or more importantly minimum drip then the washer
may need packing out with a fibre washer between washer
and brass back plate as probably reahed end of tap
shaft thread travel.
Replace at this time the fibre washer that seals off the main
thread section.
Before re-assembling smear petroleum jelly on the
threads in theory to make it easier to remove next time.
Have a cup of tea.
More plumbing.
Replacing an immersion heater or any action that requires
draining the hot water cylinder.
With hindsight it is easy to end up with an airlock in the
system and no "hot water" flow on filling up again.
It would seem logical to drain the system fastest
by opening the taps but if you only drain via the drain
cock of the cylinder then water is retained in the hot
water piping and less likelihood of forming an airlock.
If you do end up with an airlock then a matter of
connecting a hose to the lowest point of the hot
water pipe run and connecting the other end to
mains pressure water tap and blowing the airlock air away
with mains pressure. Initially with all taps open and then as water
flows in each in turn upwards/along then turn that one off and
then finally last bubbles in the cylinder.
Rolf Harris Stylophone
Nothing or just an odd beep.
The phosphor-bronze on the switches had relieved their
spring action and no longer making contact.
To gain access ,remove back cover ,2 screws ,and prize the protruding
3.5 mm socket past the end of the case.
To remove the switch parts hold one edge of the spring washer
with a fingernail and file down the rim on other side until
it can break away. When rebuilding replace with any old washer
held down against the phosphor-bronze spring action while
a dab of hot-melt glue solidifies. That way an easy job
to cut away at any point in the future
Select bass boost headphones
Cut lead and broken pivot on headset
Broken plastic mount for the partial pivot of the earshell mount.
Wrap around break area with a cable tie and melt in
with hot-melt string.The litz wire is solderable to repair cut,on each
phone there is signal and ground and the third lead is for the mono-
fashion bass signal supply on right lead and return via left lead
with join in the headset.
Set up screens (this one Akura AMCDVD-1883)
Drunken owner of DVD player managed to go into the set-up and change
setup language to German and NTSC for the UK (English and PAL)
which destroyed any semblance of a picture.
Not only that but he'd set full brightness and minimum contrast
Pressing PS/IS (progrssive/interlaced )button on the remote got some
sort of image.
With a B&W image now on a UK TV, only line-locked, and about 3 overlayed
images and because of the contrast/luminance could not
distinguish the yellow highlight from the white on the set up screen.
Turning TV to full contrast and low brightness, which only just
showed a vague difference between yellow and white,
and could proceed to alter the setup.
More generally perhaps
Unplug from the mains. Wait 30 minutes. Hold down the
power button on the machine (NOT remote). Connect to mains. On many
machines, this will force a general reset to the factory defaults
, hopefully not German and NTSC. If
it doesn't work, Google the machine and see if there is a general
reset key-press sequence on the remote.
South Western Bell FF895 Freedom Phone
Two of the number keys non-functional.
There was a dry joint on one of the 390K bank of limiting resitors in the
keypad multiplex lines.
Spectacles-Broken - well the owner thought I could solder them back again.
Lens dropped out with broken retaining channel band. Broken at the point where
the "eyelet" end of the retaining band is screwed to close and tension
this band. Not enough material to make any sort of solder repair.
Smallest brass eyelet using the solder hole end and cutting off the business end.
Bent rightangles and small hole drilled to match a drilled hole at the broken end
of the band. Also to get the tightness of right angle relieved some of the metal
on the inside of the bend to give space for the head of the retaining screw.
Used a pcb pin as a rivet to anchor eyelet to band all soldered in .
Ground back the edge of the lens to clear the protruding part of the "rivet" into
the retaining band.
Filed / ground back any excess brass,solder,pcb pin. Mount the lens and screw the
eyelet to the body of the glasses. Colour and varnish the bracing to match the
rest of the specs.
Sunrise Medical disabled charriot charger 24V,4 amp
Apparently no output. Yet again one of these that monitor
battery voltage. If seriously discharged/shorted cells then
no output from the charger,as battery voltage rises the
charging current is reduced to intermittant .5 amp
when charged.
Spin drier for woolen jumpers.
Requirements a nylon carrot sack or similar and a
pair of stout gloves. Place the wet wool jumper
in the sack , put on the gloves and whirl around
in the back garden.
Stanley Bridges ? AEG ? drill repair
The aluminium stick on labels are broken
off or worn with wear.
Must be 20 to 30 years old or even more , 1/2 inch chuck of make Rohm.
Made in W Germany, distinctive colours of yellow handle and armature
section, then boxy black section with gearbozx and hammer section. I find
the reverse , anticlockwise drive direction option useful. The levers are
orange.
Not so much for the drill has how to repair
a small motor stator coil
Got a bit tired of electronics and as my old hand drill, i only use for
counter-clockwise left-hand drilling, was playing up so I decided to give it
a birthday present of a new coil. It was supposed to be for 240V but running
off 110V via a variac was ok for my purposes, but now the part-bad coil was
causing too much variation and excess current/contact arcing for the ammeter
on the variac.
If run it on reduced voltage with monitor lines added or probes to
the stators then the bad one will be substantially lower volts than the
other one. The hot coil may well be the ok one, being forced to take more
current along with the armature, i didn't think to check that and too late
now. The original drill on 100V
had 26 to 33V on the "top" bad stator and 60 to 74V
on the other good and about .7 amps
Repaired , again on 100V , then 25V on the replacement
and 31V on the original
I removed the relatively blackened coil , that putting a meter over that
coil , in use, confirmed bad in comparison to the other. Cut through the
hank, butchering the hanks out of the slots, dousing with
paint stripper didn't seem to soften (trying to avoid breaking
the plastic faring bits) and counted turns , weighed the copper to 30.5 gm and measured the wire
diameter to about 14/15 thou and resistance of 7 ohm for both original stators
so prblems only when powered.
Does anyone know a formula for a better guide for setting up a former with the right dimensions, to wind a replacement before
squashing and placing in the channels with "gummed"
high temperature silicone tape and then swathing in lacquer.
Found a useful table in a 70 year old book.
Wire qauges one way and columns of wires/turns per sq in packing, weight per 1000
yards and ohms per 1000 yds.
29swg 4350 T/sq in , 1.68 lbs/1000 yds, 165.27 ohms/1000yds
30swg 5200 T/sq in , 1.397 lbs/1000 yds, 198.8 ohms/1000yds
I'd not realised that being W German make then
probably some metric gauge of wire on the original.
Making up a former was easier than I thought.
The former shown was just a flywheel from some old piece of
audio kit then 2 layers of motorcycle inner tube
stretched over to give the right diameter and ease removal afterwards,
and 2 large o rings to give some sort of width limit
combined with the turns of lacing cord - incidently
use wax covered as 1/2 a reef knot will bind while
you knot the second part. The coil winder described
elsewhere on this file.
The first thing to lay down is some loose loops of lacing cord, about 8
loops diametrically , 45 apart, around the former before winding the turns,
then cutting the cord into indivuidual loops and tying off after wire
winding and before removing. So the exact shape of the bulking of the wires
into a hank does not matter that much as the tying-off of the lacing cords
while still on the mandrel would form the cross-secion of the hank into a
circle. Repeated later, off the former, gives a better job.
Dimensions , from the originals /core.
Axial slots in core 0.22 inches wide, axial length of core
40mm, gap across rotor area between lips of the
axial slots 0.9 in.
diameter of rotor 32mm. Hank in core on extreme width 1.8 in,
extreme length 2.55 in and bend at ends approx .9 in.
To avoid catching the silicone tape laid in the slots
when introducing the hank. Lay down a strip of
parcel vinyl tape either side of the edges , one fixed
back to the rotor area and the other to the wall of the
core, repeat on the other slot and remove the vinyl when
finished but before lacquering. Keeps the slots open.
I thought that ovalling the axial parts to squash in the slots in the motor
core would be a problem but all went fine, though 7mm diameter when squashed
to a circle, rather than original about 6mm. The hank resistance of 7.1 ohm
compared to 7 ohm was good. I could not decide if the original was 29 or 30
swg but looks as though it was nearer 30 swg.
A rifenement is to lay a dowel or rod axial and outside the core to tie the
hank back to while pushing the axial sections into the core slots.
coil hanks
The first and second hanks, too large and too small
badly focused, with foot ruler
motor core
Background paper mm and cm.
The overall circumference was too long so the ends of the hank overhanged at the
open ends too much. I recalculate for 30 swg and had another go. There
was space in the housing to try out my first effort so did have a go assembling
and running without lacquering in, and it worked fine.
I originally thought the hank lay up would have to be over a 2 part former
like a pulley split in two, the awkward way, but with a semicircular laying
up section. Then having to manually lay-up (as the auto traverse flip is
only per item , not per layer) something like 4 turns,6,9,12,14,16,17,18 and
down again to 3 for 192 turns. But I know now that a complicated former and
intricate lay-up is totally unnecessary.
My second hank was too small and the third attempt was Goldilocks.
First calculations for 29 swg gave 201.7mm / turn
average length, 64mm diameter. Giving inside diameter
with ideal packing factor of 58mm. The former I chose for that
was actually 59.5mm but the result was far too big
,more so than 58 to 59.5mm
Second attempt, as if for 30swg
but using 29 swg gave 53.4mm av diameter and former
diameter of 48mm - too small, 5.4 ohm.
Choosing 64 mm former was about right in the end
and retaining 192 turns gave 6.1 ohm and the coil I ended
up lacquering in and using. Perhaps should have gone
to 30swg and changed the number of turns a bit.
The final used coild had a dc resistance of 6 ohm
and when drill powered from 100V, used .65 amp
and the stators dropped 24V and 21V.
Does anyone know formulae for these calculations
for the range of swg/awg wire gauges and other dimensions.?
Tamiya remote control car
No response on car
Corrosion on the recessed battery terminal (+ve) in enclosed section
not obvious even on removing part cover.
Tesoro Tejon metal detector , search coil
One of those jobs I now wish I hadn't taken on.
Intermittant problem with angle of the search coil, cable sheath cracked at
the entry point to the search coil housing , so assumed broken wire within.
No, now having Dremmel plus ball-mill excavated down through the epoxy, the
copper wire of the search coil going to the green wire exposed and the same
for the red, continuity to the multistrand wires from each of those.
But no continuity between the exposed copper wires, even with an RLC meter ,
just in case a C in there.
500 GBP cost so worth spending some more time on it
and replacement coil 135GBP.
At least there is plenty of talc filler in the epoxy, so easy to excavate.
Looks as though it is 2 hanks of 3x6 turns of 0.02 inch wire.
Laid out as 2x D shapes with the flat parts bowed a bit and overlapping at
the junctions of the straight and curved parts of the D and the join has
failed between them.
Toy automata x2- well it makes a change from VCRs etc
and kept an automata / mechanical toy nut happy.
Both mainly use metal cog trains like clockwork but instead
of coil spring use DC motors.
1) Clown on a truck (RF Alps,Japan) with bellows"horn"and front bumper
activates a latch to initiate a different set of actions: no drive
First plastic drive cog broken. Not the size and pitch of cog used
in VCRs /cassettes. Found a metal ex-clock
cog with grub screw. Drilled out to 2mm and fixed to motor
with glue on grub-screw. Tooth pitch and diameter not
quite right but powered up on bench supply and filed
down in situ first 2 cogs - well its only tin-plate engineering to start with
and quiet gear trains are not a factor.
2) Drunk panda on a barrel (Iwaya Corporation RVT 3309 GZK)
Water transfers via tube through shoulders between the cup and
bottle when arms raise.
Dead motor.
Black gunk on the commutator insulated from contacts.
Remove back plate to remove motor. Remove end cover of
motor and extract armature to clean.
Before total failure the action would jam activating the
clicking weak link/slip clutch . Filed back the abrupt
faces of the cams which was stopping at this point and replaced the
arm return springs with a lighter guage springs.
Dismantling -remove the barrel from the rest of the automata .
Peal back "fur " to expose fixing screws.
Two parts of the body shell will come away around each arm
after removing the head which needs
one screw removed to reveal the pin and extract.
The eye rolling linkage is easily bent and fouls the head rolling
linkage at the neck joggles.
Uplighter installation.
Ceramic type, firstly the mounting holes are punched
through the clay before being fired so no standard
fixing point separation.
Concerning these key-hole shaped holes - you cannot
screw up tight steel screws to ceramic so nothing
except self-weight stopping the bowls being dislodged
on cleaning - push a TWISTED WIRE JOINT "hi-scale" cone
(high temp plastic or bakelite) in th elarge hole to
wedge into position.
Urmet communal door entry system-6 flats plus tradesmans
No de-latch trigger.
Broken front panel switch broke probably because
switches mounted in pattress but buttons on top pannel.
Handyman swapped the spare unused switch to the broken
tradesman's switch position not realising this switch
is isolated and all others are commoned. DC for intercom
6,5V ps and 12V ac ,schematic inside embossed on cover of interior box.
Vessa Inter Med disabled batricart charger.
Apparent failure of charger
Not exactly a repair job but the owner was considering
spending 200UKP erroneously on a new charger.Output should
be of the order 36V at 5A.The instructions on the charger failed to say that at
least 30V had to be monitored on the leads
going to the 3x12V batteries.Any voltage less than this (ie one or more
defunct batteries) meant the charger never kicked into life.The low battery
would have to be isolated and charged with a 12V car charger or replaced.
Water leak in mains pipe.
Trying to trace a leak of only 1/4 Lt / min but very noticeable
if metered supply.
There was 4 brassy stubs
protruding from under the dial section of the water meter
and continuity to that point was 3.4 Megs. Tried injecting about 6MHz
from RF generator and sniffing with a small hand held SW reciver to
trace the pipe run. But as water piping was connected to gas
piping and both having similar runs I got better discrimination
by feeding 1KHz or so square wave in and tracing with small
medium wave receiver. Connecting to the metal pipe a DVM
and pushing a rod into soil parallel to the pipe a foot away is
no good - whether a few hundred ohms or hundreds of K did
not identify the area of leak.
Made a listening stick from some steel rod and a wooden cupboard/
drawer knob and excavated down mid way. Sound loudest at mid point
and excavated at 2 other points. Could not tell which point the noise
was loudest. No londer have access to an octave band audio analyser.
It is just possible that bassy rumbly noise is heard at a distance of 10s
of feet and hissy noise only becomes prominent withing last
10 feet or so of the leak.
Apparently plumbers often put peppermint essence in smoke, so that if it can't be
seen, there is a very good chance it can be smelled, presumably by
turning off the supply , pumping air back through the system and then
somehow connecting a container with activated smoke bomb into the piping.
Decided to freeze the pipe to zero in. If water stops at tap then
it is frozen. If meter dial stops rotating and leak noise stops then
the leak is down-stream of the freezing point.
From 2 2 pint plastic milk bottles fashioned a trough with the
screw caps at each end , hotmelt glued in the middle and
about a foot long. Open area at top and cut along into each
of the screw cap sections so can be opened and mounted around the pipe after
wrapping turns of rubber cord tied at top around
the pipe where each cap end is and finally tied tight with a cable tie
at each end. Added gummy tape around gaps as well
From crushed ice from freezer and cooking salt
about 500 g to 0.5 Lt made up freezing solution and placed in the trough.
Monitoring with thermometer the pipe froze up in about
30 to 45 minutes at about -15 degree C.
Before getting the water board to install a water meter.
Make up a listening rod as above. Turn the in the house
supply stop cock off and company pavement stop cock
on. If on holding the listening rod to your pipework
you hear a rumble or hiss it is likely you have a leak
somewhere on your side and responsibility. On the
other hand because of lorries and cars over the years
moving over pavements it is quite possible
that the leak you hear as a rumble rather than a hiss
under the kitchen sink pipework could well be a leak
in the first few feet of company property/responsibility
pipe work. In such circumstances, with no other knowledge
I would suggest the
first pipe-freezing/ isolation should be the pipe run
immediately inside your property/ground boundary.
Whatever next
Bridge/partial denture/removable prosthesis.
That is a cosmetic replacement for a missing tooth
not fully functional as far as eating is concerned.
A weird and wonderful use for a different property
of hot-melt glue - its translucency.
Using the translucent rather than white type.
Firstly assume the missing tooth is a gap
with parallel or tapering open sides rather than
tapering together - for that situation probably
two part initial mould and transverse fit final "tooth".
With children's plasticene/modelling clay in two
parts one inside and one outside press into the gap
from both sides to make an impression. Carefully
slide out and use to make a plug.
First coat with silicon oil then epoxy or polyester resin.
Not too thickly so can flex to remove from the impression
and later the final piece.
Then dribble hot melt glue from the gun to form the
final "tooth". When cold cut back to leave ledges
to outer face on either side
to engage with adjascent teeth ,cut level
"biting edge" and leave plenty on inside mating surface
to the gums. Remelt cut surfaces by holding near a soldering
iron to gloss up the surface. Make the tooth more ivory
looking by melting white and mustard child's wax crayon
into the melt to colour match or use wood type hot melt sticks.
Modified toothbrush for those people that the idea of
flossing is a joke , as teeth are jammed together.
For receeding gums along with ordinary brushing.
Start with a conventional toothbrush,
remove all bristles except the leading row , using pliers to
pull out. Fill the holes with hot-melt glue.
Hacksaw a slot behind this row of tufts.
Hold near a soldering iron to soften the plastic remaining
at the cut and open out the slot by bending between two
sets of pliers. Fill the gap with some glue. Leaving a
brush with a line of bristles angled about 45 degrees.
If the bristles are not stiff enough drape some
epoxy around the base of them , wrap some thread
around and then some more epoxy.
At this angle the bristles are more likely to get
up/down into the otherwise untouched gum area inside and out,
using a stipple action.
My dentist originally told me to form something similar
by bunching the brush bristles together between fingers
and using. I invented this cut and modified brush,
which is nuch easier to use,
told him about it, and now he advises others to do same.
A simple tip from another dentist - if you use fluoride
toothpaste don't swill your mouth around with water
after brushing - greater chance of flouride-binding.
Wickes DE44GY dehumidifier, 2001
Compressor worked but no fan
The fan mount had vibrated loose. Refixed with
star washers and glue dabs.
As only platic the rotation axis of the fan
was not true, tried propping over, and filling
the recess around the fan retainer clip with hot
melt glue to re-align.
On reassembly fix the 2 screws at the top of
the condensor radiator to hold the front white
cover on, firstly.
Window glass replacement.
Ever noticed how glass breaks of its own accord rather
than something thrown through it cracks where those
little brads are. Although headless they are still stress points
so thermal or dampness changes to the wood can start a
crack there. Use the smallest of C cable clips - plastic C
with a nail through and bury in putty/mastic - no metal
touching glass then. While at it remember to measure
the diagonals before getting the glass cut.
Wrist watch old electro-mechanical (solenoid escapement)
Failed battery with no known source of replacement.
Battery probably 4.5V in tubular form so no space to put in button cells.
The owner only wanted it in working order for special occasions and
didn't mind an access hole made in the back cover of the watch.
Ground and filed a small hole in the back to take atiny 2 way connector.
Inside a 1N4148 between it and the original battery and link to the other terminal.
Then made a simple charger from a 9V power supply ,
a series R to drop current to less than 1mA and a 5.6V zener on the output
to limit otherwise if voltage goes up over the batttery the escapement ran slow .
The watch would work for
at least 6 hours disconnected from the charger. If this battery fails will consider some SM
high C capacitors and voltage limiter instead of the original battery.
Xpelair window mounted extractor fan
Broken ball chain (bath plug chain)that holds the flap closed
and fan switched off.
The problem is this chain goes through a joggle
inside the surround and you can't just push
a wire through attached to a new chain. With
new length of ball chain held (a few balls from the end
and loose end curved upwards) with
thin nose pliers or forceps it is possible
to introduce one end into the small aperture
from the outside and gingerly let the self
weight of the chain drop vertically past
the "key-hole" anchor slot buried inside.
Then fix each end ,one to flap and other
to a ring. Or doubled back piece of copper wire
from inside to out , tie some thread and then
tie the ball chain to the other end.
If the motor fails to switch off due to the flap
distorting with age then fix a small
stainless steel bolt through the flap opposite
the trigger switch to pad out.
A squirt of WD40 for sticky switches.
Diverse Devices,Southampton,England
Telephone number - the same number as it has been since 1988
but email is now the preferred method of contact so number deliberately not placed here.
I devote time each day to replying to emails.
(obscure/obsolete components,second hand test equipment,
schematics etc)
Postal: 66 Ivy Rd,St Denys,Southampton,England SO17 2JN
There is no point in contacting me about any of the above, the
repair job may have been done 15 years ago .
I cannot clarify or enlarge on any of the above.
If this email address fails then replace onetel.com with fastmail.fm or
replace onetel.com with divdev.fsnet.co.uk part of the address and
remove the 9 .
Please make emails plain text only , no more than 5KByte or 500 words.
Anyone sending larger texts or attachments such as digital signatures, pictures etc will have
them automatically deleted on the server. I will be totally unaware of this - sorry, again
blame the spammers. If you suspect problems emailing me then please try using
my fsnet.co.uk account.
More hints & tips and repair briefs on
homepage http://home.graffiti.net/diverse:graffiti.net/