Peavey (sorry) Deuce VT amp problems, help...

[chikov]

I know that Peavey amps are inferior to the amps we deal here on this forum, but a friend of mine asked me to help him with this otherwise good sounding amp. About 6 months ago I replaced all the old electrolytic power supply caps and the amp was working great but lately it developed this strange problem. when you strike a note or a chord on a guitar the sound goes out loud at first, then quickly dies with a raspy sound trail. Here is the demonstration of it:https://youtu.be/uYoecXzaE90
My question is, I am positive that all 4 output tubes (6L6) are good, so, what else can cause this type of a problem? Maybe you had a similar problem in the past. BTW, I retouched all the power tubes' solder joints and the pots ones too.

As I was searching for the source of the problem, I noticed that Power Amp input is not working either. Here is the video of that issue:
https://youtu.be/XsF4i9bUuhY
Again, Am I not doing something right? Could those problems be related? Thank you for a slightest help you could give me.
Here are Schematics:

[didit]

Hello -

Did you replace all of the electrolytic capacitors throughout. There are several in the power supply and signal path of solid state section, and those will all also be ready for full retirement.

But no, I've just limited exposure to those fine '70s era amps.

Best .. Ian

[chikov]

No, I Have not replaced any of 22 caps in the preamp section, but I will check into it... Makes sense. Thanks.

[pompeiisneaks]

Also from what I hear they were and are actually pretty damn nice amps, People just crap on them because working on them can be a PITA. I wouldn't know as I have only worked on one for a buddy, did a cap job but it was pretty easy imo. Dumble even liked their transformers for some of his builds.

~Phil

[chikov]

I wanted to give y’all an update. The problem was a resistor and the output tubes’ screen circuit. Here are a couple of photos:

2801B000-EA78-4061-BE37-DBAA82C1CD43.jpeg

18A8AB33-9ED0-4FB4-B205-68ECCE8C2221.jpeg