Where to find 6000uF 50V replacement cap cans??

[RG100ESROX]

Anyway, let me know what you think, and if you need any further clarification or additional voltage readings.

Jay, I'd like to ask you to measure voltages at the following points:
1. base and emitter of Q10
2. collector and emitter of Q11
3. collector and emitter of Q12

I suspect we'll need to rearrange the schematic. I suspect the same...

TIP 31C/32C
  B1/C2/E3

1. base and emitter of Q10 - B = -.697 E = -.089
2. collector and emitter of Q11 - C = +41.22 E = -.040 
3. collector and emitter of Q12 - C = +.510 E = +41.04

[Miyagi_83]

As you can see...where I once had -.6 (as indicated on the schematic) is now +.521v. I don't even know how this is possible. But, this is the case.

Now, if I look at the back side of the PCB. I honestly do not see how the bias trim pot can be located in the circuit as indicated in the schematic. However, and again, I used to get -.6VDC on the bottom lug of the bias trim pot as it is indicated on the schematic before I broke the amp. So, how does it go from -.6VDC to +.521?

Are you absolutely, 100% sure that it used to be -.6VDC and not +.6VDC? Are you certain that your memory and / or notes serve you well on this one? If that particular leg of the trim pot is connected to the base of Q11, and it seems it is, at least judging by the voltage readings, according to the original circuit diagram there should be and should have been a positive voltage there. What's more, the original schematic says the voltage there should be roughly twice that, it says 1.2 V on the schematic, after all.

[RG100ESROX]

As you can see...where I once had -.6 (as indicated on the schematic) is now +.521v. I don't even know how this is possible. But, this is the case.

Now, if I look at the back side of the PCB. I honestly do not see how the bias trim pot can be located in the circuit as indicated in the schematic. However, and again, I used to get -.6VDC on the bottom lug of the bias trim pot as it is indicated on the schematic before I broke the amp. So, how does it go from -.6VDC to +.521?

Are you absolutely, 100% sure that it used to be -.6VDC and not +.6VDC? Are you certain that your memory and / or notes serve you well on this one? If that particular leg of the trim pot is connected to the base of Q11, and it seems it is, at least judging by the voltage readings, according to the original circuit diagram there should be and should have been a positive voltage there. What's more, the original schematic says the voltage there should be roughly twice that, it says 1.2 V on the schematic, after all.

Absolutely sure. 101%....

If you notice on the schematic it actually denotes -.6v at that point on the trim pot. I measured it many times before breaking the amp and it was -.566v when the trim pot was FCCW.

[RG100ESROX]

As you can see...where I once had -.6 (as indicated on the schematic) is now +.521v. I don't even know how this is possible. But, this is the case.

Now, if I look at the back side of the PCB. I honestly do not see how the bias trim pot can be located in the circuit as indicated in the schematic. However, and again, I used to get -.6VDC on the bottom lug of the bias trim pot as it is indicated on the schematic before I broke the amp. So, how does it go from -.6VDC to +.521?

Are you absolutely, 100% sure that it used to be -.6VDC and not +.6VDC? Are you certain that your memory and / or notes serve you well on this one? If that particular leg of the trim pot is connected to the base of Q11, and it seems it is, at least judging by the voltage readings, according to the original circuit diagram there should be and should have been a positive voltage there. What's more, the original schematic says the voltage there should be roughly twice that, it says 1.2 V on the schematic, after all.

You are correct about the voltage. There is supposed to be +1.2v on Q10 and Q11, and -.6v on the trim pot. That's why I found it interesting that the voltage was the same at those two points in the circuit, and that's why I highlighted them in yellow. None of it makes any sense to me at all. Now, I cannot verify that the voltage used to be +1.2, because I don't remember checking it. But, I absolutely  remember checking the trim pot at the noted location many times, and it WAS -.6v.

[Miyagi_83]

Ok, here's your voltage chart with added readings of requested transistors.
Looking at the numbers on the diagram, measurements for Q11 make sense to me. Those for Q12 don't. Take a look:
The collector of Q11 is connected straight to the +41V rail. According to your readings, the collector of Q12 is at +41V too, which suggests those two terminals are connected, but they shouldn't be. Q12 is in the negative leg of the power supply, so IMHO its collector should be negative in relation to ground. Unless there is a mistake in labelling of course.

Let's look at Q10 now. According to the schematic, its base is tied to the collector of Q8 and R41. R41 is tethered to the positive power supply rail. The original schematic shows a value of 38 V at the collector of Q8 and, consequently, base of Q10.

Personally, I would try to track the connections between different components on the PCB and compare my findings to the schematic so as to establish what is what and what connects to what. It'd be time-consuming and probably frustrating, I know, but I'd do that nonetheless. Perhaps it's unnecessary, I don't know. Let's wait for the more experienced players to chime in.

Here's my $0.02.

[RG100ESROX]

Ok, here's your voltage chart with added readings of requested transistors.
Looking at the numbers on the diagram, measurements for Q11 make sense to me. Those for Q12 don't. Take a look:
The collector of Q11 is connected straight to the +41V rail. According to your readings, the collector of Q12 is at +41V too, which suggests those two terminals are connected, but they shouldn't be. Q12 is in the negative leg of the power supply, so IMHO its collector should be negative in relation to ground. Unless there is a mistake in labelling of course.

Let's look at Q10 now. According to the schematic, its base is tied to the collector of Q8 and R41. R41 is tethered to the positive power supply rail. The original schematic shows a value of 38 V at the collector of Q8 and, consequently, base of Q10.

Personally, I would try to track the connections between different components on the PCB and compare my findings to the schematic so as to establish what is what and what connects to what. It'd be time-consuming and probably frustrating, I know, but I'd do that nonetheless. Perhaps it's unnecessary, I don't know. Let's wait for the more experienced players to chime in.

Here's my $0.02.

I am going to take your advise and reverse engineer the PCB with a bright backlight and see how the components are TRULY connected once and for all. It'll be a good day or two. I'm going to take my time and triple check everything before posting my findings.

[g1]

Sorry but your memory of what voltage it was before is just wrong. Don't take it personally, my memory is not infallible either.
If you did measure -0.6V, it was at some point that is supposed to be connected to the trimpot but is not (like Q12 base). 
Way back in post #107 you reported +0.5V and commented that the schematic shows it should be negative.
Earlier at post #105 you were 100% sure that Q8 and Q9 were 2N5484.  Then in post #107 you realized that was not correct and they were 2N4401.
Memory is not what we wish it to be.


Your voltages prove that the trimpot is arranged more like I showed in post #110.  It is impossible for it to have been -0.6V at the trimpot when the amp was working normally.
Re-reading page #8 (posts 105 to 119) would be very worthwhile.