Ampeg SVT-3 PRO - no bias voltage - low and distorted output

[spunko]

Hello, I have this SVT-3 pro with low and distorted output. Wanted to check the bias and there is no volatge across any of the mosfets resistors (R32 to R39).
Checked Q2, Q5 and Q6 and they all seem fine. AP1 trim pot is working, tested with my meter. Q5 and Q6 had been replaced in the past.


What else should I check?
I need help. Thank you very much.

[The Dude]

Are you looking for millivolts, or is your meter set to read millivolts?

[Jon Snell]

Q2 5 & 6 possible short C to E.
Q3 & 4 may be open circuit.
BE CAREFUL or you will damage other components if you do not test these correctly.
Don't throw parts at it!
Find the damaged component and replace it, if indeed there are any damaged components.

If AP1 has a dirty wiper, it will go high resistance and turn off Q2 as an example.