Peavey Ultra 60 clean channel only

[evilive69]

I picked up a Peavey Ultra 60 (410 combo) and initially it was changing between the clean and Ultra channel, but now it is not.
The clean channel works but when I press the channel button I hear a relay click but I do not get any sound out of the Ultra channel. If I press the button again it goes back to the clean channel and sound comes out.
I did some reading and I would guess it is a relay, but I am unsure which one or how to test it.
Any help would be great.
Thanks.

[Enzo]

A relay COULD be the problem, but then so could ANYTHING in the Ultra channel. A bad relay could keep a good Ultra channel from sounding, but just as likely a good relay would switch to an Ultra channel that was not working. Apply a steady signal to the input. I use a CD player to keep my hands free. Then trace the signal through the bad channel to see where it disappears.

[evilive69]

Thanks for the advice. I pulled out the new tubes I just installed one by one and found a bad one. That was the issue.

[evilive69]

Dup post