Fryette master volume woes

[Seashore]

My Pittbull 100CL has been with a repair guy up here in VT for a retube. I just picked it up today, brought it home, plugged it in, and it's doing the weirdest thing. It's basically behaving like the master volume is set somewhere around 1 or 2. The knob itself turns but has no effect; turned all the way down or all the way up, the output stays at the same low level. All the other controls seem to work normally. It's just stuck at low bedroom volume. I've had this amp for 16 or 17 years and never experienced this before.

I don't work on amps, but, does anyone have any idea what might be going on? Is this the kind of thing where I could replace the pot or just fix some wiring, or am I in danger of being zapped if I touch the MV wiring? Sorry if these are dumb questions and I know it's not always easy to diagnose problems over the internet. I'll take it back to the guy and ask him to make it right if I have to - he does a lot of amp work and seems well qualified, maybe just rushed this one - but it's a 4 hour round trip.

[beaubrummels]

Sounds to me like the master is bypassed. Can't think of a reason for that to happen just retubing and biasing. Can't tell if the shop caused it, or just something happened to fail at the same time. If you don't work on amps, I'd have them look at it again.

[jeremy]

you want to unplug the amp from the wall and drain the filter caps before you poke around in there. once you do that, its not dangerous. that said, it doesnt mean youll be able to diagnose the issue. i would call the guy up, explain whats going on and take it from there. might be as simple as a ground wire lifted but could be a bunch of different things

[Seashore]

Thanks guys. I texted with him and looked at couple of things he wanted me to check out, but didn't see anything obviously out of place. Looks like I've got no choice but to bring it back in.

[Seashore]

It turns out that one of the screws holding the chassis onto the underside of the case was slightly longer than the others, and when the tech put it back together, he put that screw in the hole that just happened to be directly under the MV pot, and it was in contact with the wiring. Quick and easy. We had a good little laugh about it and he pointed out the sections of the amp that could kill me if I touched them and I got to mess around with a Parker Fly for a little bit. Long drive this morning but it could have been worse. Everything works now. My takeaway is, make sure you have a long screw in the right place when you're getting your head.

[jeremy]

glad it was something so simple!

[Seashore]

glad it was something so simple!

Me too... I feel like a dummy for not trying to figure it out myself but I wouldn't have known to look for this, and it wouldn't have been apparent when it was out of the box. He only remembered the mismatched screw because he'd put it back together so recently.