Peavey 5150 combo - No output

[RobRR]

So an old friend brought me a 5150 combo to look at... he got it on a trade (he's not a musician) and it doesn't work.

It turns on, both power and standby lights. The power tubes glow, only one preamp tube glows, but that's because all the others are Sovtecs that really don't normally glow (or so I'm told?). The amp has absolutely no output, tried the effects loop, speaker out, nothing, not even a hum. Strangely enough, i can hear a little bit of sound coming from the amp itself with no speakers plugged in?

Took the electronics out for inspection (I know my way around electronics, what not to touch, etc) and there are no visible signs of damaged components, blown caps, broken traces, fractured solder joints... everything looks as it should. I've done a lot of reading/searching but can't really come up with much. Any ideas where to look next?

[Carbuff]

So, youre saying that youve tried an external cab to rule out a blown speaker?

[DonP]

Strangely enough, i can hear a little bit of sound coming from the amp itself with no speakers plugged in?

That's likely the sound of the amp being pissed off. Never run a tube amp without the proper load or you'll be replacing expensive parts.

First check for blown fuses. Then I would start with replacing all the tubes with known good ones. I don't care if they glow or not.