I thought about putting my tongue on the capacitors to see if they are still good but decided against.
Tube or solid state rectifier?
I wish I remembered what failed, but we had a really good sounding Crate vintage tube 33W 2x10 (sadly, I have forgotten). I think it was part of the rectifier circuit That caused a crackling and drifting radio station kind of phase thing. Complete pain in the ass because the construction was surface mount technology. Not worth repairing.
Check your preamp out and your power amp in and see if somehow you get a good signal. It'll help you troubleshoot a little bit.