3/02/2017

General Electric T1000B Stereo Refurbish


I have been watching for a GE 1000 stereo for quite a while, this one has been listed on ebay multiple times and always at ridiculous prices.
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However they finally came to their senses and dropped the price to something reasonable. I received it today. It was somewhat well packed but the AM antenna had broke loose, thankfully it did not break. The glass is not cracked, but the silver sheet behind the knobs is wrinkled, I will attempt to fix this later.
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I always wondered why shipping on these radios was really high, well this thing is very heavy. I estimate it has at least 5 lbs of 1/16" steel in it, the entire front part of the chassis is a single steel plate.
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Oddities for this Stereo:
Weight 28 pounds
10 tubes
The AM/FM/STereo knob is mechanically linked to it's switch on a sub chassis.
it has a large flywheel on the tuning knob like more high end tuners.
a 12at7 that is the MPX input amp and the 19kc OSC-doubler.
2 12ax7's, 1 for the phono preamp, and one for the Radio AF amp.
Single ended 6aq5a's for beam power tubes.
BASS Boost Couplates.
A power transformer outputting 150v .122A and 6.3v 3.5a.
No "stereo beacon" light.
Speakers are connected to the radio through the hinges.
External speakers can be attached to the stereo either by connectors on the speaker enclosures, or the back of the stereo. attaching external speakers does not appear to disconnect the internal ones, unless you un-hinge the external ones. It appears that the hinged speakers can be disconnected and then connected to the external connection on the back for wider separation.
Speakers are the weird inverted cone type.
speaker cloth on both sides of the speaker enclosures so you can listen with the enclosures open or closed.

First thing I did was test all the tubes and clean their sockets. All tubes tested ok and may be original as they all have the same date code? 188-5.
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I took the chassis out.
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The process involved removing 8 screws; 3 from the underside of the radio, 3 under the inside top and 2 on the right side near the output transformers. I de-soldered the hinges at the tie points; 1 near the large multi-section capacitor, and the other behind the angled bracket near the output transformers. Then the hard part, the 6 knobs on the front are metal and there is glass behind them so you cannot pry up on them with a screw driver or whatever. I took some scrap wire and shimmied that behind them, and gently rocked them while pulling and they eventually popped off.

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various circuit boards.
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Look at all that steel! I like how all the circuit boards are mostly accessible.

The first repair I did was to mount the AM antenna with new cable clamps, and re-solder it to the tuning capacitor where it broke off from.

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The next repairs on the list are to check and probably re-solder ALL the circuit boards, and replace the Electrolytics. The seller stated that it was working but I will not be powering it up till the electrolytics are replaced.

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Here are the pictures of the Electrolytics:
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The seller reported this thing had booming bass. I would not say that, I would say that it sounds like listening to a stereo someone crammed inside a cows stomach.

I located the bass boost couplates and shorted them. The bright orange discs in the picture below. they consist of a 1 meg resistor bypassed by a 100pf capacitor.

If you have one of these I highly recommend doing this mod, the stereo sounds a whole lot better, less muddy and throbbing. I will note it inside the chassis and it can be easily undone.

As to the #12 lamps... I went to a local surplus electronics store and happened to find some bulbs that looked like #12's they were labeled as #15, sadly they are #15's and will not work. The problem with #12 bulbs is that when they show up on ebay people want ridiculous prices for them as they are used in certain Lionel train accessories. There are some sellers that want between $3 and $11 a piece for them.

I removed the #12 bulb mounts and installed 2 bayonet mounts for GE 47 bulbs. I screwed and soldered one of them and soldered the other to the chassis. I angled them to better match the location and height of the old bulbs, otherwise they wont fit in the cabinet.
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47 bulbs are the same voltage and amperage as #12's 6.3v .15a

I checked all the resistors on the Tuner chassis and they all checked out good... EXCEPT the resistors above the tuning capacitor, almost every one of them was out of tolerance and one of them was open.
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The out of tolerance caps were (per Sams):
R7
R8
R10
R11
R12
R6 was open
R5, R9 and R70 were ok.

of course all the resistors I had to replace were in the most difficult to reach spot on the whole radio. I blame excessive heat for their being out of tolerance.

I checked and replaced resistors on the MPX board. I had to remove the angle bracket from the chassis to access the board better. of the 15 resistors on the mpx board, I replaced 7. the 2 blue resistors on the lower right of the picture were replaced not because they were out of tolerance, but because they output audio to the output board and I wanted them to better match.
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one trace on the board pretty much came completely off and I had to tie the 3 resistors that used it together. These traces are held on with good intentions and not much else.

In between working on it, I listen to it, and it keeps sounding better. Of course I am listening to it through a pair of Monarch bookshelf speakers (coincidentally on the bookshelf above my bench). I don't know what it sounds like through it's factory speakers (yet).



I decided to take a break from the resistors and look in to the glass panel and silver backing. There is what looked like black specs between the glass and the silver foil.

I took it apart and found (to my dismay) the black specs are actually missing silver and the black backing material showing through. Which means it has to be replaced.

This is what it looks like:
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It looks like tiny sequins or trout scales. It's pretty tough stuff, although I did tear it once while removing it.
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The material was applied in layers:
reverse painted Glass
Silver mylar like material
Thick black vinyl like material
Thin black mylar or nylon like material stuck to...
steel plate
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I went to Michaels and there were several options, all of which were very sparkly and gaudy. I found some stuff that looks almost exactly like the foil that is in the radio but not as shiny. It is called "Diamond Texture foil" item number 267532. It is just not as shiny chrome as the original. It's close enough for me.

I replaced 13 of 20 out of tolerance resistors on the output board. This was probably the most difficult one to work on because many of the resistors are under the bundles of wires. The 3 resistors at the top are in series to replace the 120Ω 1 watt resistor that I do not have.
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Some were so hard to get to that I snipped them out and installed them on the solder side of the board.
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Several could only be tested by being disconnected because they gave very high readings or would not give a stable reading.

I temporarily put the dial glass back in the cabinet, and then used that to mark where 1600kc is on a strip of painters tape mounted to the front of the radio.

I pulled the chassis out and using the mark as a guide I marked all the other spots on the dial called for in the AM and FM alignments. I expected more but all the instructions called for was 1600kc, 1400kc and 98mc.
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I identified and marked all the IF cans, with thier top and bottom designations in that same order. I marked the corrected test points per Braithwaite. I located and soldered wires to the hard to get to test points on the multiplex board. In the process I found another out of tolerance cap behind the 12at7 (v6) it was an 820Ω and is also test point D.
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AM was pretty much still in near perfect alignment, I only tweaked it slightly and adjusted the dial tracking slightly better.
FM was also in near perfect alignment (not anymore) :cry: If yours sounds good? LEAVE IT ALONE! I have done FM alignments before, and even stereo alignments (I have the equipment) but every time I do it's not pretty, and usually takes several tries.

Test points B and C are NOT reversed on the Schematic but they ARE reversed on the Tuner Chassis Component ID page in the Sams. On the Tuner Chassis Component ID page B points to pin 4 of the Couplate and C to the Resistor connected to Pin 1 of the Couplate, reverse that (look on the couplate for the pin numbers). Pin 4 of Couplate K3 (C) exhibits plus and minus voltages as it is supposed to. Test point B only shows a peak as it is supposed to. However IF transformers A13 and A7 ARE reversed. When doing step 5 I found that a DMM works well as I had trouble getting my VTVM to center on zero in the middle of the dial. You just have to go slower with the DMM.

I had a lot of trouble with the alignment, first my sweep generator was not working correctly or I do not know how to hook it up :oops: I switched to using the DC VTVM but still had problems due to the inconsistencies of the instructions, and (as I found out just before I gave up for today) IF transformer L5 (A12 A11) had a cold solder joint and was reeking havoc with my attempts to do the alignment (now resoldered).

If you insist on doing the alignment you will need to make this viewtopic.php?f=10&t=285415 You insert it in between the tube and the Shield of V2 (FM Mixer). It is a tight fit but the tube shield has a split and can be expanded for it to fit. Use paper based tape, it won't burn but it might melt if it is plastic. (my invention)
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You may find that A14 does not do anything (or very little) and you won't be able to move 98mc on the dial. Don't give up, to the right of V2 is a large copper coil (seen in the picture above) carefully expand or shrink the open coil to bring it in to proper alignment (not in the instructions).

Re-soldering L5 did the trick, and I figured out why my sweep generator was not doing what it should. The instructions call for putting a capacitor between the Signal generator and the ungrounded shield around the FM Mixer (V2). Well my sweep generator RF output probe already has that and adding a second one seemed to greatly attenuate the signal.

This time the alignment went smoothly and quickly.

The only issue remaining is that I have to turn the balance far to the right to get proper stereo.

This stereo has always had this issue and I am not sure if it is caused by one of the output channels or if I need to do the stereo alignment.
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 Applying the background to the plate for the tuning dial went pretty quickly and easily. I used a light coating of some spray on contact glue applied to the face of the plate and the back of the diamond texture foil, carefully aligned it with the top and left edge and then gently smoothed it from the center out.

I trimmed it from the back side using a NEW (very important) exacto knife blade. Be very careful that you cut all the way through the paper and foil. You can see at the bottom where I did not go all the way through and when I removed the excess paper it pulled some of the foil off. This won't be seen so it is not a big deal. I used a hole punch backed by a block of tape covered aluminum to punch out the holes for the pot shafts.

When I cut out the large rectangular hole I removed the piece pushing it through from the front (foil covered) out the back to avoid tearing or pulling the foil off the paper backing.
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I did the stereo alignment.
There are 2 problems with doing it:
The instructions are not clear.
A17, A18, A19 are completely stuck (possibly glued in place).

I was able to adjust the 19kc Pilot settings, but not in the way they said. The instructions say to input the 19kc in to pin 2 of V6 (which I did) but when I adjusted them as described the stereo signal was wonky and there was a hum that increased or decreased in pitch when A15 and A16 were adjusted. This meant the pilot was off. Instead what I did was, I have a Leader LSG231 stereo generator, I outputted the composite signal from that to V6, set it to L+R hooked the scope up to the speakers, made sure the radio was set to stereo. adjusted volume and balance, alternating with adjusting A15 and A16. I adjusted A15 to get the beat frequency nulled, and A16 to get the sign wave traces to match. I would then (while listening through head phones make sure the balance was even. This was made difficult since there is a bias in my stereo to the left side, and I think it is because one or more of the tubes is slightly weak on the right side.

I replaced the "weather stripping" from the front of the radio.
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I re-glued the rubber strips to the top and bottom of the dial glass using tacky glue (I do not want it to be permanent).
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Putting the dial glass back in the radio was difficult as there are wooden blocks that help hold it in place, these blocks fell out. I figured out where one went but the small one I just guessed. The long one I glued back in place, but I just wedged the other one in. The rubber kept binding and not wanting to stay where it should on the glass, but I got it in properly.

I found that the FM dial does not track accurately even though 98 is lined up properly. I think there is more to the alignment then Sam's has in the instructions. I would probably need an actual GE service manual to get it to track right. Since it works and sounds good I am not going to mess with it anymore.

I put the back on and cleaned the power cord.

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The dial light works as it should, however without the dial light it is hard to read the reverse painted letters on the dial glass, which was the case with the original silver backing.

It sounds great with the OEM speakers, there is no need for the bass boost couplates, there is more than enough bass and with the speakers closed the bass is further reduced. Stereo separation is perfect (adjusted for my left bias). The left bias exists even with an mp3 player connected to the phono input.

1/07/2017

Federal Ten Ten Heresy stereo "boom box" build

I built a small radio/boom box using the case from and old Federal Ten Ten and various and sundry parts.
I used for the radio one of these:
http://www.ebay.com/itm/291692426129?_t ... EBIDX%3AIT
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The is an AA-AB32155 from Parts Express (15 watts per channel):
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in the last couple of years I Bought 2 of these:
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The first one was a VHF low version that only worked in the 30mhz range and was useless to me. The second one was the VHF High version but was dinged up. Luckily this radio can be completely disassembled and I was able to make the VHF high look good as well as get the correct crystal I needed.

The remaining Ten Ten had a broken antenna and while it worked, I have no use for a 30 mhz radio. I gutted it and am now in the process of building speaker mounts. I also was able to fix the antenna using one I had purchased in a lot of 12 from ebay. I will be building a small 12 volt linear power supply (Possibly regulated). The speakers are 2 - 4 or 8 ohm (not marked) speakers that I got from somewhere (maybe computer speakers).

 I found a piece of brass for the panel to mount the speakers to.
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Painted the front of the panel.
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Cutout the space for the radio, mounted it, the speakers, battery, and the amplifier in the case. Wired up the the external power and the antenna.
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I had reversed and painted the speaker cover as the original finish was in bad shape.
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The switch is just and on/off switch as the amp does not have a volume control, the volume is controlled by the radio or the remote. I have to open the back to charge the 2200mah LIPO. The amp draws 2 amps at full volume (supposedly) and the radio draws a max of 500ma. At normal listening volume the radio could run for several hours on battery. There is a 2 amp fuse on the battery.

Total time to build about 10 hours.

 Some minor finishing touches (a name tag).
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Labels and charging connector for the battery on the back of the radio.
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Yes it sounds pretty good and puts out more volume than I would ever need.

10/22/2016

Battery Charger build

A while ago I had acquired an old 8 amp selenium rectifier car battery charger.

I took the parts from that and built a new one.
 
But I needed a case. I had discarded the old one.

Recently I found this Brumberger film carrier:
 
 I drew up plans in autocad for the front and back:
 
I laid them out on the front and cut the holes out.

The timer I got is a Haydon Model ADI 1A001C D130302.
The actual timer on the back is a General Time E15450 A2631A1 timer.
The cover plate (which is a sticker) says OFF, EQUALIZE, and NORMAL CHARGE. It appears the only source for these is here: http://www.electronicsurplus.com/haydon-1a001c-d130302-0-16-hours-adj-timer-120v-spst-28a





The unit has 2 black wires for 120vac 60hz and 2 spade connectors for the switch. The switch can handle 250vac 28 amps. The shaft is a standard D type.

I will use a 25 watt 10 ohm POT's so I can vary the input voltage to the transformer. This charger originally had selenium rectifiers so the output voltage is about .5 volts too high. I need to reduce that and do not have any diodes that can handle the 14 amps that this charger can put out before the self resetting circuit breaker kicks in. I want to vary the input voltage anyways to experiment with some of the charging methods I have been reading about. I only need to adjust between 1 and 8 ohms to reduce the input voltage from 125 vac to 115vac if needed. My wall voltage can get rather high sometimes. I do not want to use a variac. I also do not want to over complicate the charger with a DC voltage regulator.

The finished unit:
I used a 50 amp quick disconnect so I can connect the charger to standard clamps and to other types of connections.
There is only one fan on the back, the bottom is just a vent hole.
The timer is set by moving it clockwise or counter clockwise to either "normal charge" or "Equalize". The timer moves clockwise and opens the charging circuit when it hits off. The separate power switch means that the fan will continue to cool the unit once charging has completed.

8/20/2016

Funai Magnavox TB110MW9A has green light but does not power on


Funai Magnavox TB110MW9A does not power on.
Symptoms are:
green light flashes and then stops flashing and stays solid green.
nothing but snow on the tv.

My wife's aunt had this problem. I replaced hers with a different model but decided to see if I could fix it. I opened it up to look for swollen capacitors but there were not any.
I tested the voltages in the power supply and the voltages on all the voltage regulators. They all seemed ok. Finally (with some fiddling) the unit came on. I started carefully moving things looking for the problem. The problem ended up being the small vertical card with the large chip on it, If I moved it the unit would lose picture and go to snow.
The fix was to re-solder all the tabs on it.
That was it. It now powers up and shuts down properly.

7/08/2016

Starrsoft Win96 Win500 won't load in Windows 7

I have a legit copy of Win96 and Win500 and for reasons I do not know they both stopped working. Searches of the internet showed lots of solutions for citrix and terminal servers (which these files are not on) nor are the files on a network share.

The solution is to go in to System properties, Performance Settings, Data Execution Prevention and to add the win96.exe and win500.exe to the list of exceptions. Below are the error message related to the problem.
---------------------------------------------
Fault bucket 2762246838, type 1
Event Name: APPCRASH
Response: Not available
Cab Id: 0

Problem signature:
P1: Win96.exe
P2: 0.1.7.4
P3: 4eef5003
P4: StackHash_9f4e
P5: 0.0.0.0
P6: 00000000
P7: c0000096
P8: 00bd340e
P9:
P10:

Attached files:
C:\Users\xxxxx\AppData\Local\Temp\WERD494.tmp.WERInternalMetadata.xml
C:\Users\xxxxx\AppData\Local\Temp\WERE883.tmp.appcompat.txt
C:\Users\xxxxx\AppData\Local\Temp\WERE893.tmp.mdmp
C:\Users\xxxxx\AppData\Local\Temp\WERE8D3.tmp.hdmp

These files may be available here:
C:\Users\xxxxx\AppData\Local\Microsoft\Windows\WER\ReportQueue\AppCrash_Win96.exe_dd1f1d933413637c13bbca2e1e0dda3edbdb166_cab_53a9e8fe

Analysis symbol:
Rechecking for solution: 0
Report Id: 7fe17232-457c-11e6-b628-00224d88aa25
Report Status: 12
---------------------------------------------
Windows cannot access the file  for one of the following reasons: there is a problem with the network connection, the disk that the file is stored on, or the storage drivers installed on this computer; or the disk is missing. Windows closed the program Win96 Scanner Utility because of this error.

Program: Win96 Scanner Utility
File:

The error value is listed in the Additional Data section.
User Action
1. Open the file again. This situation might be a temporary problem that corrects itself when the program runs again.
2. If the file still cannot be accessed and
    - It is on the network, your network administrator should verify that there is not a problem with the network and that the server can be contacted.
    - It is on a removable disk, for example, a floppy disk or CD-ROM, verify that the disk is fully inserted into the computer.
3. Check and repair the file system by running CHKDSK. To run CHKDSK, click Start, click Run, type CMD, and then click OK. At the command prompt, type CHKDSK /F, and then press ENTER.
4. If the problem persists, restore the file from a backup copy.
5. Determine whether other files on the same disk can be opened. If not, the disk might be damaged. If it is a hard disk, contact your administrator or computer hardware vendor for further assistance.

Additional Data
Error value: 00000000
Disk type: 0
------------------------------------------

Faulting application name: Win96.exe, version: 0.1.7.4, time stamp: 0x4eef5003
Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc0000096
Fault offset: 0x00bd340e
Faulting process id: 0x2630
Faulting application start time: 0x01d1d98942198782
Faulting application path: C:\Program Files (x86)\Win96\Win96.exe
Faulting module path: unknown
Report Id: 7fe17232-457c-11e6-b628-00224d88aa25
------------------------------------------
Fault bucket 173410711, type 17
Event Name: APPCRASH
Response: Not available
Cab Id: 0

Problem signature:
P1: Win500.exe
P2: 0.2.0.7
P3: 533b3d88
P4: StackHash_8066
P5: 0.0.0.0
P6: 00000000
P7: c0000096
P8: 0076340e
P9:
P10:

Attached files:
C:\Users\xxxx\AppData\Local\Temp\WER72A7.tmp.WERInternalMetadata.xml

These files may be available here:
C:\Users\xxxxx\AppData\Local\Microsoft\Windows\WER\ReportArchive\AppCrash_Win500.exe_9cafbefff092ed2c6d7981ef5fbc5ec017761a_5b3286c3

Analysis symbol:
Rechecking for solution: 0
Report Id: 9800ad92-457c-11e6-b628-00224d88aa25
Report Status: 0
------------------------------------------
Windows cannot access the file  for one of the following reasons: there is a problem with the network connection, the disk that the file is stored on, or the storage drivers installed on this computer; or the disk is missing. Windows closed the program Win500 Scanner Utility because of this error.

Program: Win500 Scanner Utility
File:

The error value is listed in the Additional Data section.
User Action
1. Open the file again. This situation might be a temporary problem that corrects itself when the program runs again.
2. If the file still cannot be accessed and
    - It is on the network, your network administrator should verify that there is not a problem with the network and that the server can be contacted.
    - It is on a removable disk, for example, a floppy disk or CD-ROM, verify that the disk is fully inserted into the computer.
3. Check and repair the file system by running CHKDSK. To run CHKDSK, click Start, click Run, type CMD, and then click OK. At the command prompt, type CHKDSK /F, and then press ENTER.
4. If the problem persists, restore the file from a backup copy.
5. Determine whether other files on the same disk can be opened. If not, the disk might be damaged. If it is a hard disk, contact your administrator or computer hardware vendor for further assistance.

Additional Data
Error value: 00000000
-------------------------------------------
Faulting application name: Win500.exe, version: 0.2.0.7, time stamp: 0x533b3d88
Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc0000096
Fault offset: 0x0076340e
Faulting process id: 0x28f8
Faulting application start time: 0x01d1d9895a37ff92
Faulting application path: C:\Program Files (x86)\Win500\Win500.exe
Faulting module path: unknown

4/17/2016

Interesting little crystal tester I got from ebay

I saw a video by Joernone where he shows a crystal tester he built. I thought that would be pretty cool to have but I did not have some of the components to build one. While looking to order them I found a completed board that does all the same things plus a go/no go light for a pretty reasonable price.
http://www.ebay.com/itm/Electro-Resales-Crystal-Tester-and-RF-Generator-XTRF-/152053865120?

I bought the board, made some minor modifications to it, and mounted it in a project box.
Here are the results:

I went through all the crystals I had, I only found one dead one, a couple that oscillated strangely, and almost all of the crystals were spot on (or very close to) their rated frequencies.

4/10/2016

ViewSonic VA2431 LCD Monitor problems

I received this monitor from my work several years ago and it was working perfectly up until a couple of weeks ago.

My monitors are calibrated, and when I do certain things like:
login through remote desktop and then login from the console or
play minecraft and exit the monitor loses it's settings and I run a special program to restore the settings.

Lately my monitor had a pink cast to it that would not go away when I ran the program to restore the calibration. I thought maybe it had lost it's calibration so I did a fresh calibration and that seemed to fix it... for about  20 minutes, then it went pink again. I did another calibration and it seemed to work but after 5 minutes it started flashing between pink and calibrated.

sigh™

I opened it up and it did not appear to have bad electrolytic capacitors but I replaced them anyways. I tested the old caps and all of them were leaky including the large 450v filter cap.

Now it works fine.