CPD1604S Vertical Collapse
 

So I got this Sony PC monitor from 1992 that didn't work when I picked it up. I went ahead and tested all the caps and replaced anything bad. There was a absolute ton of caps that had gone high ESR (we are talking 300kOhms high) and there is one board in particular, the DA board, that used surface mount caps which had leaked all over the place.

On the DA board, I removed all the caps and clean it thoroughly with white vinegar and let it sit until it stopped foaming. I cleaned that off and then soaked it with 99% IPA and dried it off with compressed air and let it sit for days to make sure it was dry. The DA board is almost all surface mount, and there are no transformers or anything that might get messed up by being wet. I sprayed all the pots with deoxit and fiddled them a bit to make sure they didn't harbor salts or crust from the whole process.

I also inspected the DA board under a microscope and tested continuity on any areas that seemed more corroded. There didn't appear to be any such issues, and the traces didn't seem to be broken, only exposed in some areas. I suppose it's possible that something under an IC is bad, or a via got damaged because it's a multi-layered board with components on the back side. There is absolutely no apparent damage to the back side.

When I got everything back together, I turned on and I got HV, but the image was vertically collapsed. It's only a few pixels high, but it's there enough that I can actually make out the colors in the line and it reflects what should be seen on the screen. For example, I can see where the Windows logo starts and stops on boot, and I can see the proper colors change on the raster horizontally (for example a SMPTE bar image will reflect the bars color across the screen). I can also successfully shift the image horizontally with the screen controls.

My first thought was that the bad caps on the D board might have blown the Vertical Output IC before I got it, as I have run into that issue a number of times. I bought a handful of the ICs pretty cheaply, but replacing it didn't help or apparently change anything. I thought maybe the replacement could be bad, but a thorough check of the original IC revealed no shorts on the IC, and diode tests between pins seem to make sense for a working IC. I don't believe the original IC was bad at all. I suppose it's still not impossible, but I think it's okay. Anytime this has happened to me in the past, the IC had shorts or low resistance between GND and Vcc or some other pin(s).

So I'm kind of lost here just checking random things. It's extremely difficult to test voltages on this monitor because the portion of the case that holds the CRT is extremely thin and can't be supported by it's structure alone. The only way I could get it to stand up and make adjustments on the inside was to prop it up leaning forward on a towel and balance it that way. Doing this it's not possible to access the bottom of the PCB to take readings. So I disassembled the chassis again and I'm just looking more closely at the DA board in hopes that I can find a culprit.

There are a number of small ICs on the DA board that handle all the V and H stuff, and choosing the resolution, I assume based on the frequency of the incoming signal.

Can someone help me to identify which components or areas can cause this condition?

Again this is:

-General Vertical Collapse

-There are still a couple of pixels present, enough to match what you are displaying to those few lines as the input changes

-Horizontal seems to be okay in that it spans the whole screen and it is movable with controls

-High Voltage appears to be present as I'm getting the whine and the static on the screen

-Area around the Vertical output IC on the PCB is dark from heat, but none of the component are visually burned or bad and testing a couple so far they looked perfect.

Here is a link to the three pages of the schematic on imgur. I didn't want to put them in-line as they are 11x17 size and would be too big here. If you open the image links and then view them in another tab, you can expand them to see details.

D board:
https://i.imgur.com/WPsfh6y.png

DA board:
https://i.imgur.com/cd66Twn.png

Neck board:
https://i.imgur.com/sW2mfuv.png

TIA

I did some more work on this project and was able to get things balanced in such a way that I could take some readings with my scope.

What I found was that I am getting what appear to be correct waveforms on the DA board when I have a standard 31kHz VGA signal plugged into the monitor.

I tested several TPs, but specifically I was able to confirm that I'm getting both proper Vertical deflection signals in from the VGA cable, and that the Vertical Deflection signal looks exactly as the SM says it should when it leaves the DA board.

I'm not sure if this means I can rule out the DA board completely, but I am more suspecting that the Vertical Deflection just isn't spinning up at all.

I already replaced the Vert output IC, and replaced the caps around it (and every other bad cap on the board), so I don't know what to try next.

Also have checked the windings on the yoke and they seem to read what I would expect in both cases.

Any ideas?

So I isolated the 24VDC rail to the Vertical output IC as the culprit and traced the issue back to a fusible resistor at the transformer. It most likely blew as a result of bad caps in the power supply that I have replaced, so it's getting Vertical deflection now.

Unfortunately, I'm still having some issues with the Geometry. I can't seem to get the Pin Amp controls to straighten the sides out.

After much tweaking around with the various controls, I think it's got to be some component in the Pin Amp section of the DA board that is wrong.

Any ideas on what to focus on?

This is the section of the schematic that contains the Pin Amp stuff, and you can see the whole thing in my first post via the imgur links.

https://i.imgur.com/ElXADDR.png

I think you probably missed a cap in there. Caps are high fail in these. Then there's the vertical output IC also.

Nope. Didn't miss any caps. Especially not on the DA board. It's a tiny board that was mostly surface mount caps. Took em all off and all the through hole caps as well.

As I said in my last post, the Vertical is working now, unless you think the Vertical output IC could have an effect on the Pin Amp circuit on the DA board?

I did replace the Vertical IC with an NOS part, so there could be something wrong with the new one, but I don't think it's specifically handling the East West stuff, that's on the DA board.

It's using a TEA2031A for the geometry adjustments, and when I spray the thing with cold spray it gets wiggly and it looks like it's pulling the sides in. So I'm suspecting that one. I can get it cheap so I just got one coming regardless.

Attached is the datasheet

Indeed it can be the IC, but you changed also the low value electros in this area?

Yes, I had to change all the low value eletros. All the surface mounts spilled their guts, and the few through hole caps were quite bad. I checked the orientation of the caps many times, I didn't make any mistakes.


I tested the Pin Amp IC:

Pin 5) correct. 20 Vpkpk square wave @ 31.15kHz

Pin 6) correct 20VDC on it

Pin 7)14VDC offset from schematic is present, but the 0.5Vp-p waveform is screwy and wrong. It looks more like a sawtooth than what the schematic shows, and it's only about 250mV, not 500

Pin 8) 3.4 V pkpk sawtooth. Very close to the 3.6V pkpk shown in the service manual.

So from this I can conclude that something is fishy around the chip or inside the chip. Pin 7 is connected to ground through a 150k resistor, but in this set, it's also connected to the rest of the circuit through a 470k resistor with a cap to ground between them. I have no idea why it's done, but I can guess that maybe it's some kind of DC restoration to bring the level of the chip up to the rest of the circuit on pin 7 or possibly to enable some of the other geometry controls in some way.

Pin 7 is connected to Pin 5 through the one resistor, and the waveform on Pin 5 looks correct, so therefore, I'd basically assume that there's either something wrong with the chip, or with one of the components going to ground between the Pins.

R376- 150k - to GND from Pin 7

C340- 0.0015 - to GND from Pin 7

R375- 470k - between Pin 7 and Pin 5

Does this result say anything to you about the circuit or the failure I'm seeing; it's like something in the circuit is bring down the 500mVpkpk parabola I'm supposed to see to ~280mV and squishing the top down into noise

I attached the expected waveforms from Pins 5,7 and 8 of the Pin Amp IC, Pin 6 is the supply is supposed to be 20 V and it is.

Makes all sense. We can imagine the waveforms differing a little according with CRT variances, but certainly not a radical difference. At least with my experiences with modern TV when I repairing it (and monitors), is that the waveforms always resemble the originals when it are working well. Besides the suspicious DC voltages.

Thanks. I went ahead and probed Pins 1 and 2 of the Pin Amp IC, and it seems like the AC component that's supposed to vary the parabola on the IC's output is not properly varying when I adjust the Pin Amp potentiometers.

I am now thinking it's most likely the fault of the IC, but also maybe it's some other component in the circuit holding the IC down at the input or output.

Does anything jump out to check?

Be sure the V out is getting + 24 VDC. I hate shot gunning BUT if
it has @24 V change the IC & all related 'lytic caps, ALL at once.
While things are removed do resistant tests. That will fix 95% of them.

Zeno:smoke:
LFOD !

Yes, it's getting 24V out of the transformer now. I also scoped Pin 6 on IC303 (East West IC) and it has the indicated 20.5V supply. In fact, all of the Pins around IC303 look hunky dory except Pin 7, which is suppose to be the parabola.

I changed all the caps on the DA board already because they were the early surface mount kind and were all dead. So unfortunately I can't do resistance tests with them out of circuit.

I've got a new East West IC coming on monday, so I'll try my luck with that and cross my fingers. Otherwise, I might have to remove the caps and start looking for an open resistor or something.

I replaced IC303 and I still have the weird Side Pin issue. I've been checking resistors all over the board, pulling stuff out when I have to, but I'm still not seeing any issues.

If anyone has an idea of what would maybe cause this to narrow my search I would be grateful.

So this is the output of Pin 5 on IC303. I realize now that the top of it is the key to understanding the pincushion adjustment output. If you look at the top of the waveform, it's supposed to have a flat top that extends past the edges of the square wave evenly on both sides.

This waveform is incorrect as it has the top portion skewed all the way to the left. The waveform wiggles around in a manner that perfectly reflects when I tweak the Pincushion pots, and it snaps back to the left as the sides of the raster similarly refuse to be corrected.

https://i.imgur.com/cGyMb8O.jpg

Now I can see why it's displaying incorrectly, but I don't know why or where the problem lies. I've already spent a long time checking voltages, and nothing really seems wrong so far. I've more or less confirmed the values of all resistors, and I checked the ICs that control the mode selection.

Where should I focus my attention?

To add to the last post. This waveform is shown in the Service Manual here, and it shows that it's supposed to have a symmetrical top portion. Also of note is that the DC voltage on the output of Pin 5 is called out as 4.6V in the SM, but it measures 8VDC with a DMM.

The output of Pin 7 is also incorrect; it's a smooshed sawtooth looking thing and nothing like what it is supposed to be. I have to assume something is wrong either on the input side (Pins 1&2) or the output side (between Pins 7 and 5, or further downstream from 5).

I see the basically correct symmetrical 6.4VDC on pins 1&2 (SM says 6.5, but that's pretty close I think), but the parabola is driven by current and not voltage, so I'm not sure if just having those two correct voltages is enough, and I'm not sure how to tell if there is imbalance in the current draw (or what to do with that information if I had it).

I've followed the output as far as the last set of transistors in the Pincushion circuit (which control the Pin Balance), and the voltages at those transistors appears to be correct.

https://i.imgur.com/O6M2OaQ.pnghttps://i.imgur.com/7bxIy2I.png

I am still bewildered by the Pincushion issue, but I found an area of the circuit that seems to be a little amiss.

There's some readings that are what I would call "shaky," or that they bounce up and down a bit on the scope and are hard to lock in with the trigger.

Also there are some areas that the voltages are a little bit off; nothing is extremely off, but there are some spots that look about 1V or so off.

The "worst" of these spots is around Q312, which is supposed to be 9V on the collector, but it's a little above 10V and bounces around up and down. The base is supposed to be 3.9V, but it's 3.3, and the emitter is supposed to be 3.2V and it's 2.7V.

Normally, this wouldn't look like a smoking gun to me (and it doesn't really), but I'm not seeing anything else much wrong still, and it's right in the "Side Pin" circuit, which is a prime area that looks to be malfunctioning.

I'm sure I am measuring the circuit with the correct conditions (31kHz, color bars), and everything else on the DA board is almost dead-nuts under these conditions, so I believe I have it right.

So I ordered up some 2SC1632's and I'll start off by replacing Q312 and see if that helps. If it does nothing, I can try Q311, 314, and 315 as the are all in the same circuit and all have a tiny bit of voltage variation from the SM, but none of them are more than Q312 is.

This is my readings. Green is dead-nuts, Yellow is slightly off in some way. The yellow circled resistor values are all in circuit, so I expect them to be off. Of course, if any of those looks weird, then please let me know. Sorry it's so messy, but that's how I've been keeping track of things.


https://i.imgur.com/9K2n3LJ.png

If it bounces in a undetermined random time, some R, C or some transistor (like the ones you will replace) must be with some issue. Some internal corrosion etc.

I figured as much. I can't imagine the ceramic chip caps or the resistors are at fault because they are such simple devices, and at least the resistors are basically reading the correct values (I haven't tried to remove and test all the little caps).

The transistors and maybe diode seem to be more suspect because they are more complicated devices that could be partially effected by some small amount of internal corrosion. I tested the diodes in the area for leakage and they seem good too, so I feel like I'm left with one or more marginal transistors creating sneaky havoc

Yes, the best bet is the semiconductors. Yet, if all are good, don't give up:
https://www.worldphaco.com/uploads/R...SONY_MICRO.pdf
In this example, the restorer found a 100R noisy R in the AFC circuit.

True it's always possible. Probably a lot less so with 90s resistors than with the resistors in that early 60s Sony set.

I won't give up, at least not anytime soon. I fixed a shortwave radio once that took me years. I had to put it aside for awhile and the when I came back to it fresh it kind of clicked and I figured it out.

Although, this is looking pretty much like I'll have to brute force things to some extent.

All I have currently is some slightly wrong voltages, so I'll start there.

This long time occurred to me more than one time. Last time, was with a delta-gun TV, with a jittery unstable vertical only half a minute in a 2 hours interval (absolutely random); and after the hiccup, the vertical changed linearity a little (sometimes a lot). When I stomped in a convergence pot, finally I discovered the trouble... of course, vertical output is CCS, so a variation of the convergence resulting impedance will distort the vertical due to load variation. Took me 2 years to discover it... I cleaned the offending pot, and the problem never returned.
Also time to dedicate to it are short, so I used it as-is when symptoms are more light, until it become worst.

I replaced the IC303 with another part, and the other transistors in the 300 range, which are largely related to the Pincushion circuit. After getting it back together, I checked voltages and found that some of them are correct now that were slightly off before, but I have one new issue that I didn't have before.

I found that I have lost width control, and there is some kind of short or something going on that I have not been able to track down the cause of at all.

The Pincushion IC is connected to the Vert position circuit through Q255, the collector of which is connected to Pin 2 on IC303. It is supposed to be 2.2V at the Collector of Q255, and then end up at 6.5V at Pin 2 of IC303.

Basically what's happening now is that the voltage at Pin 2 of IC303 changes with the Vertical Position pot, which is obviously wrong. I've checked all the transistors and diodes in the area and can't find an issue. I also checked IC205 for shorts between pins and found nothing.

There is 22V at the Emitter of Q254, which will change the voltage present at the bottom of D257, and then raise the voltage at the base of Q255, which finally raises the voltage at the collector of Q255 and that voltage shows up on Pin 2 of IC303.

It's also possible that something in the switching section of the circuit is functioning incorrectly as perhaps if the various diode arrays were getting the wrong input somewhere, it might lead to a weird mixed outcome for the cumulative output. The connection between the Vertical position circuit also is impacted by the switch which goes between the presets and the external V/H size and position controls. The switch is not a simple on/off, but a ground/not ground signal sent to the anode of D609, which turns Q615 on or off.

FYI, the service manual wants me to take all voltages and waveforms with a 640x400 70Hz color bars pattern, which is what I have been doing.


I replaced Q254 and Q255 with brand new exact replacement transistors (all of the SMD transistors and diodes are still available cheap for this PCB thankfully), and I tested D257 and it looks like a working diode. It's a Diode package that has one anode and two cathodes.

The junction betwen D257 and Q254 is 22V when it should be 7.7V and I really can't figure out what's causing it at all.

Any ideas?

https://i.imgur.com/YOEec95.png

Hmmm... multiscan monitor... a lot of things to see...

22V? The IC are responding ok to the logic on it's inputs (the IC250)? Or, if something ahead the P302 are throwing this voltage (eg. with RV257 closed)?

Likely, some cascade of events can occur.

I'm not sure how to check if there's an issue with IC250. I checked for shorts, and there's no shorts between any of the pins; all pins are no connection to each other.

From the datasheet, there doesn't seem to be a way that 20+ volts is produced by Pin 10 unless there is some internal short?

This is why I though the 20+ volts is coming from somewhere else further down.

Transistor arrays are new to me. This one looks this way on the inside:

https://i.imgur.com/N5uVcGq.png

An array is a simple form of IC not having power supply sometimes, so rarely have any processing. Basically the cause can be external to it (sometime trowing 20V there).
Anyway, the pin 9 must have higher voltage than the others, or the internal diode conducts.
The problem must be with any of the outputs if it don't reacts with the input.

And so I measured the logic circuit approaching IC250 and I found a problem with inputs on IC604, which directly feeds the network of transistors leading to the inputs of IC250.

Pin 1 of IC604 is LOW when it should be HIGH. This is causing Pin 5 to be LOW when it should be HIGH.

I traced the input for Pin 1 IC604 back, and it's connected to the collector of Q613, and also to the 12V line through some resistors.

The Base of Q613 is connected to the output of D609.

D609 is switched on and off by the Auto/Manual switch for the horizontal and vertical size and position. The switch goes between GND and Open Circuit.

D609 measures correct on it's other side (toward Q615), but it reads 2.7V on the side towards Q613 when it should read 0V.

I can see that the input of Pin 1 on IC604 being wrong will cause certain problems, but I can't tell if this problem is because D609 give incorrect voltage, or because the 6.5V which should be present on the other side of Q613 is not there for some other reason.

I also cannot see why this possible "cascade" problem would create 24V on Pin 10 of IC250. If I had to make a guess, I would tend to believe there is an issue creating the 24V on Pin 10 of IC250 and that is leading to, or also causing the loss of 6.5V on other side of IC250.

I measured all other logic ICs in this circuit (IC601, 602, 603, 605, 606) and I found that all voltages were correct on all pins of all ICs.

I replaced Q613 with a new part of the exact same transistor (they are still available) and that didn't fix it. The old transistor measured to be a bit weak and measured different from new part, so I thought it was worth a try.

I have replacement ICs for logic coming in the mail, luckily they are all also available and very cheap.

This is what I am seeing, with incorrect voltages in red:


https://i.imgur.com/IecusN1.png
https://i.imgur.com/DQFelQo.png

So, the AUTO switch, connected to GND, can extinguish Q615 and Q613, unless have some fail in this line.
The IC 604, it follow the truth table in the datasheet? Too busy at moment to analyze it but, a question: perhaps 0V in the pin 1 causes 0V in the outputs?

Yes, IC304 definitely follows the truth table of its datasheet. The incorrect voltage on Pin 1 causes 0V on Pin 5 output.

https://i.imgur.com/pxbhIdS.png

Pin 1 should be HIGH, and the 4 outputs it controls should all be HIGH, instead it becomes HLHH

So the 2.7V on base of Q613 maybe is the problem. Or possibly the lack of 6.5V on the collector of Q613 causes the 2.7V to appear on the base.

I don't know the chicken or the egg unfortunately


Edit: I'd like to add that I isolated IC250, Pin 10 to try and see where the 23V is coming from that shouldn't be there, and without Pin 10 connected to the rest of the circuit, it no longer has the 23V on it, but I still see 23V all over Q254 and the Vertical Position potentiometer. Not sure why it's wrong, but I also can't see how it's connected to the issue with IC604.

Also makes wonder if D608 are not resistive or open, or some trouble with this line (the circuit/switch for the AUTO/Manual are inoperative?). Certainly one function corresponds (the one making GND connection) to basically near 0V on the cathode of D608. Then the cathode of D609 will presents very low voltage I suppose. Unless...
The cathode of D609 is connected to another thing in the circuit, or is only to Q613?

I can say at least that switching Auto/Manual control does indeed still switch the control mode. The horizontal size doesn't work at all, but the position controls all work somewhat. The vertical position "works," but it shows up in the wrong spot (too far down).

The cathode of D609 (right side) goes only to the base of Q613, nowhere else. It's at 2.7V. The collector of Q613 is supposed to be 6.5V, but it's 0V, the emitter of Q613 is grounded.

The other cathode touches Q615 and IC602/604, but that voltage is correct.

The anode goes to the switch between GND/Open and the two resistors that connect it to the 5.5V rail.

The main problem I'm seeing is the lack of 6.5V on Pin 1 of IC604. That bad logic sees the circuit between it and the other two diode arrays, IC250 and IC302 incorrect. But I don't know if the problem comes from D609 side or IC250/IC302 side. Can bad voltage(s) on output side of those ICs cause cascade failure back towards D609?

You can see that lack of 6.5V on the circuit to the right of IC604 has a lot of problems for the logic. It flips the logic level on 5 Darlington pairs inside IC250 and 4 pairs inside IC302.

https://i.imgur.com/APQxtke.jpg

A little more troubleshooting has ended with my now losing the raster mostly. If I turn up the G2 a bit I can see something, but it's all messed up.

If I display something with color it doesn't seem to come up, it's just a murky white raster, but it will sync to a black and white image a little bit if i tweak the free running horizontal frequency to match it

I pulled IC250 and IC320 and they test normally and identical to a new part, so I think they are okay. Pretty much every part I test is okay, and yet things are still wacky over by those two ICs.

I did notice that the voltage on Q317 is also very off, I'm assuming because of Pin 10 of IC302, and that it's connected to a relay on the D boards. Although I don't see how that would effect things, I can tell there's some switching problem with the Multiscan circuit because it's not kicking thing into gear correctly.

The only other lead I can think of is that I had to replace Q310 twice already before things went totally south. It's now acting just fine I believe, so perhaps whatever is wrong now is somehow related to Q310 blowing previously.

Q310 was involved with this area where I thought there was an 18V zener diode missing (but it turned out after looking at photos that it was unpopulated). Once I replaced Q310 the voltages in this area all started looking good, but then it developed this new (seemingly worse) issue.


https://i.imgur.com/SJEU1xF.png

So the multiscan not operates correctly? We presume then the wrong auto setted voltages as a result.
What is the scan rate detector, a µcontroller or a bunch of logic IC's?

A bunch of logic ICs and discrete components.

The Horizontal and Vertical Sync signals come in directly from the VGA cable to the Multisync PCB, while the color information is sent directly to the Neck PCB.


EDIT:

Ok, I managed to get the raster back to what I had last week where I can see the image, but I do not have (much) Vertical Position control. I have Vertical Size, Horizontal Size, and Horizontal Position, but Vertical Position is just a tiny little bit, and it's always basically too low down on the raster. I have no Pincushion controls (even less than when I first started).

I removed IC604, IC250 and IC302 and replaced them with new parts and just kind of did my best to reflow anything I had reworked and that made the raster come back.


I still have the problem with Zero Volts in the area beyond Pin 5 of IC604.

I switched the resolution to 1024x768 to see how that would change things, and I am seeing 18V on the base of Q317, which I don't think should be there. This connects to a Relay on the D PCB, so I thought maybe it's a problem on the D board, but I measured the Pin on the connector that goes out to the RELAY and it's around 4.3V while the Base of Q317 is 20V. It interacts with Q616, so I measured the Base of that and it's at it's correct 5.5V, so I don't think this is a problem over there.

I guess it must be all coming from the other side of the circuit?

Okay, I maybe tracked down a possible cause, but I'm not sure exactly what might be wrong.

I followed bad voltages around on the board, and I found one that I can trace back to the D PCB through the Vertical Position Signal (which seems to be what's FUBAR).

The Base of Q255 connects to D257 and to the D PCB through Pin 19 of P302. This should be at 8.3V but it's 1.3V. This has got to be wrong I'm thinking.

This 8.3V is supposed to be driven by Q202 and Q203. I actually did think that this might have been contributing sometime a couple weeks ago, so I pulled these two transistors and they tested okay with a simple diode test out of circuit.

I measured the voltages on Q202, and the other two voltages are pretty close to correct, so something here is amiss.

Again, I still don't really understand this stuff totally, so for all I know, the 1.2V is being pulled down from the other side where D257 and Q255 live.

This is what the area looks like:
https://i.imgur.com/pIyNfiv.png

https://i.imgur.com/4s7KRMN.png

With 0V on pin 11 of these IC, indeed we can have low voltage in the V_POSI.
So the command for this IC can be wrong (like wrong scan detect or some fault, or false protection detection maybe). If the IC is good.
But then, Q203 must follow it and then this emmiter voltage needs to be low, or it is inoperative.

Thanks Alex

I measured Q202,203 and I found that the Base-Emitter was very higher, like 1.5V which is way to high, so I assume it's toasted and that would explain the lack of 8.3V.

I am wondering if this situation can be responsible for the lack of 6.5V on Pin 1 of IC604?

There's supposed to be 25V on Pin 11 of IC250. This is missing because the 8.3V is missing on the Base of Q255 and the Anode of D257.

Maybe the 25V on Pin 11 of IC250 closes the transistor input at Pin 6 (of IC250) and bring it to zero. That closes anodes of D255 and then zero volts appears at Collector of Q612. This causes 6.5V to flow through Base of Q612 and to the collector of Q613 and Pin 1 of IC604. Possibly make sense?

In this explanation I am suggesting that the input of IC250 (Pin 6) is being pulled high because of the lack of voltage on its output (Pin 11)

I traced out the voltage path to look at how it's flowing and maybe how it should flow:

https://i.imgur.com/I6hMbrT.jpg

The pins 2 and 3 of IC604 are with proper correct levels? I presume these being from the scan rate detector section.

Yes they are correct. Pin 2 is at 5.2V (supposed to be 5.5, but seems close enough), and Pin 3 is at 0 volts. All Pins on IC604 are correct except Pin 1 and Pin 5.

I spoke a little with someone who has suggested to me that the 2.7V on the Base of Q613 is probably correct, and it's because the Service Manual must use the "Manual" setting on the Auto/Manual control which grounds out the D609/D608 OR Gate switch.

I had been assuming that the switch was supposed to be set to "Auto" for schematic voltages because Service Manual mentions to use "Auto" setting for setting up voltages and frequency potentiometers on the board in the setup instructions, but it doesn't actually ever say what setting that switch should be at for the schematic voltages.

So doing the math, this person was able to figure out that 2.7V is the correct voltage for that spot when the Cathode of D609 is biased towards the Base of Q613.

So that 2.7V is a red-herring and the whole Auto/Manual switch area is fine. The problem is all on the Collector side of Q613.

I think pretty certainly that Q203 is the cause of the missing 6.5V on Pin 1 of IC604.

This is still not clear if it will fix the problems with the Pincushion circuit that I started with though. I am hoping that it will because I can see that the missing 25V on Pin 11 of IC250 is both the cause of the missing 6.5V, and it also connects to Q255, which is connected directly to Pin 2 of the Pincushion IC303. Pin 1 and 2 of IC303 are responsible for creating the parabola which effects Pincushion control, so if a bad voltage on Collector of Q255 effects the current present on its Base, then it could be the whole source of the problem.

I think the determination will be if Q203 is newly broken, or if it was already starting to fail before I got to the monitor. I think there is a case to be made that the 24V line might have damaged Q203 because it's connected to that supply. There was some failure on the 24V line before I started working on it which I fixed by replacing the fusible resistor. Probably caused by all the bad capacitors inside.

I ordered a couple replacement transistors which seems to be close enough to the ones that came out, but I won't get them until probably Monday.

I got my replacement transistors and installed them. I now have all the correct voltages on those places I was concerned about.

I also now have my parabola on Pin 7 of IC303, but it's not right. The voltage is something like 2X what the SM calls out, and it looks all messed up, especially if I try to tweak any of the Pincushion controls.

Not sure what would be specifically responsible for the parabola being too big; the voltage at this point is basically correct, so it's more like something in the current generation I guess. I think the issue must be in the controls for the Side Pin or near it. Nothing I can find from Service Manual voltages.

https://i.imgur.com/kCjS9WI.jpg

https://i.imgur.com/bJfs9P3.png

Yes, this is current-driven and/or generated.
this TEA IC are "class D" output (chopped), so a interference here is nrmal. But, if parabola is larger and image is ok, is nothing to worry (for example). Assuming image are distorted, something in the current path are wrong (good to re-check the TEA datasheet). For trying to reduce the parabola amplitude or gain.

So I found that IC304, which generates the Horizontal Width Voltage, was regulating 22.5V and it wasn't changing with the potentiometer RV314. I swapped it for a new one and now I have most of my Pincushion controls back. It's definitely still a little hampered, but all the controls are now clearly doing something. There's still some kind of issue with the Side Pin controls as they jump around too much and too quickly. It's like when you have a bad potentiometer and you skip across dirty, broken carbon traces.

Except I know the pots are all fine because I removed all of them from circuit and tested them carefully for smooth continuity to the wipers from both sides.

I don't know what is possibly left to swap out. I have a new IC301, but the signals coming out of that IC seem fine. I also have new logic ICs for the switching stuff but, again, the switching seems fine.

I suppose that maybe it's just something sinking a little current and pulling down on the parabola a bit, so the ICs wouldn't have to be totally bad to cause an issue?

The main remaining issues is the Side Pin controls really. They don't quite work completely as expected.

The area I fixed:

https://i.imgur.com/ocWvzos.png