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

[RG100ESROX]

I have replaced all of the transistors from Q8 thru Q16. So, they're all new.

I believe Q8 and Q9 are the 2N5484s near the bias trim pot???

I just caught this.  Q8 and Q9 should be TIS98, not TIS58 or 2N5484.  They should be bi-polar transistors, not Fets.  What were the originals and what is in there now?

The originals were 2N5484s, and that's what I replaced them with...2N5484s.

The transistors closest to the bias trim pot are Q9 and Q8...Q8 is on the right, and Q9 is on the left.

I'm starting to think the schematic is NOT correct. The 1W 1.5K resistor (49) does not connect to the 1K resistor (48) that is connected to the trim pot. The 1.5K is connected to a 1K resistor, but it does not connect in any way to the trim pot.

[g1]

It's not possible for the power amp to work with Fet's (2N5484) in the Q8 and Q9 positions.  So either you are mistaken, or it has never worked for you. 
The power amp can't work until there are proper bi-polar transistors in those locations.

Q12 is the TIP32 with NO heatsink, R54 is the brown 100R below the black connector in the photo.  Straight down from there below the diode and cap is R48 the 1K.  The end of R48 that connects to Q12 base should also connect to one of the trim pot lugs.
If you don't have the connections, you will have to look for broken or burnt traces on the other side of the board.

[RG100ESROX]

It's not possible for the power amp to work with Fet's (2N5484) in the Q8 and Q9 positions.  So either you are mistaken, or it has never worked for you. 
The power amp can't work until there are proper bi-polar transistors in those locations.

Q12 is the TIP32 with NO heatsink, R54 is the brown 100R below the black connector in the photo.  Straight down from there below the diode and cap is R48 the 1K.  The end of R48 that connects to Q12 base should also connect to one of the trim pot lugs.
If you don't have the connections, you will have to look for broken or burnt traces on the other side of the board.

I do get continuity from the 1K R48 to the base of Q12. However, I get no continuity from either side of R48 to the trim pot. I will check the traces on the other side of the board...again.

Now, there is continuity between the second TIP32Cs collector and the trim pot lugs... Which there should be after going through two diodes...?

Well, before I even saw your reply, I was looking at the schematic and it dawned on me that Q8 and Q9 are not 2N5484s. They were 2N4401s. So, yes...I was terribly mistaken...

Well, after realizing this, I replaced Q8 and Q9 with the 2N4401s that used to be there, and wouldn't you know it? We have some different voltages. Yep. Total fault of no one's but my own. )-8 My apologies.

Here's the new voltages I took off of the trim pot and the two TIP32s and the TIP31C.

Q12 - TIP32C = -6v/-30v/-92mV
TIP31C = .5v/30v/-12mV
TIP32C = 29v/.5v/30v

Trim pot = 240mV/.6v (should be a negative voltage I believe? -.6v)

Q8 = -.8v/29v/29v
Q9 = -20v/29v/30v

I'll check the back side of the PCB again and see what I find.

[Loudthud]

Were the 2N5484s put into the board without crossing the legs or twisting the part around ? It seems like the TIS98s would have the Base as the middle leg, but the 2N5484s would have the Gate on one end.

The 2N5484 is rated at 25V BV(GSS) so not likely to survive in the power amp circuit.

[RG100ESROX]

Were the 2N5484s put into the board without crossing the legs or twisting the part around ? It seems like the TIS98s would have the Base as the middle leg, but the 2N5484s would have the Gate on one end.

The 2N5484 is rated at 25V BV(GSS) so not likely to survive in the power amp circuit.

Yes; they were. More than likely, so I discarded the 2N5484s that were removed from the board and replaced with the 2N4401s.

[g1]

With series components in a circuit, it usually does not matter the order of them.
So with the 2 diodes and the trim pot, it's possible the order on the schematic does not match the board layout.
The schematic shows the trim pot below the 2 diodes, but it could be placed between them, or above, and it would still work the same.
If you are seeing a connection between the trimmer and Q10 collector, I guess the trimmer may be schematically above the 2 diodes.

Sort of like this:

You cannot view this attachment.

[RG100ESROX]

With series components in a circuit, it usually does not matter the order of them.
So with the 2 diodes and the trim pot, it's possible the order on the schematic does not match the board layout.
The schematic shows the trim pot below the 2 diodes, but it could be placed between them, or above, and it would still work the same.
If you are seeing a connection between the trimmer and Q10 collector, I guess the trimmer may be schematically above the 2 diodes.

Sort of like this:

You cannot view this attachment.

Okay. Good info. Thanks for the visual. It helps a lot.

I will confirm the circuit layout/order when I get back home this weekend.

I failed to mention that I had ordered and received some 2N5458s to replace the 2N4401s in the event that they tested bad. So, I was thinking straight at some point. Not sure where the train went off the rails. I must have replaced the 2N4401s with the 2N5484s purely by accident, or what is more likely...I wasn't paying attention.

Anyway, thank you for all of your assistance. You have no idea how much I appreciate it.

I'll respond this weekend at some point with the info about the circuit layout.


-Jay

[RG100ESROX]

I did find continuity between the diodes and the bias trim pot circled in red. And you were right. I did not find it in the order the schematic would have you believe it was in...

What's our next move? (-;

[g1]

I think at your last check the voltages were pretty close to the values shown in the ovals on the schematic? (aside from bias string due to schematic differences)
Verify around 1.2V at Q11 base and -0.6V at base of Q12.
If those are good, check voltage drops across R55,56,57,60 and see what kind of range you can get for those values by adjusting trim pot.

[RG100ESROX]

I think at your last check the voltages were pretty close to the values shown in the ovals on the schematic? (aside from bias string due to schematic differences)
Verify around 1.2V at Q11 base and -0.6V at base of Q12.
If those are good, check voltage drops across R55,56,57,60 and see what kind of range you can get for those values by adjusting trim pot.

Thank you!!

Will do!!! I'll be back.

[RG100ESROX]

R55, R56, R57 and R60 had zero volts on them (0.0V) No matter where the bias trim pot was set...

Base of Q10 (TIP32C) was -.6v (this voltage did increase as I increased the bias trim pot.)
Base of Q11 (TIP 31C) was .486v
Base of Q12 (TIP32C) was 30.0v

[g1]

I think you are getting Q10 and Q12 mixed up.

[RG100ESROX]

I think you are getting Q10 and Q12 mixed up.

Okay. So, from left to right it must be Q12 (TIP32C), Q11 (TIP31C) and Q10 (TIP32c) is by the bias trim pot??

[g1]

Yes. From before 

Q12 is the TIP32 with NO heatsink,

Also, from the schematic you can see that Q10 gets positive supply (at emitter), Q12 gets negative (at collector).

Post voltages for the various points along the diode string, then we can figure out the order (because it doesn't match schematic).
DC volts at both sides of each of the 2 diodes, and at both sides of the trim pot.

[RG100ESROX]

Yes. From before 

Q12 is the TIP32 with NO heatsink,

Also, from the schematic you can see that Q10 gets positive supply (at emitter), Q12 gets negative (at collector).

Post voltages for the various points along the diode string, then we can figure out the order (because it doesn't match schematic).
DC volts at both sides of each of the 2 diodes, and at both sides of the trim pot.

Closest diode to Q12 -.6v |< -10.3mV
Diode closest to the trim pot -10.3 |< 269mV

Top lug of trim pot = 269mV
Bottom lug of trim pot = .457v

Still have 0.0V across both .27R and .62R resistors.