Peavey studio Pro 112

[blugrassspecial]

The channel button, Lead or Clean, only works in the OUT position which is clean channel, when pushed in amp kinda goes dumb no sounds at all.

[DrGonz78]

There is a relay K1C in the amp for switching channels. When toggling between ch1 and ch2 do you hear that relay make a clicking noise at all? Start with that first to make that observation. I have a schematic of that amp, but not sure it is the exact one, many model revisions.

[blugrassspecial]

Thanks for the reply !!! Button goes in and stays in so I know it works but I really do not hear a click ?? and as I mentioned the amp kinda goes dumb but only in that position. I will look for model numbers to try and get a clearer date of manufacture
Again Thanks

[Enzo]

All you know is that the button works mechanically.  What you don't know is whether the contacts inside the switch work.

[Roly]

Enzo, if the switch controls a relay, and operating the switch goes from one mode to nothing and back, it follows that the switch is operating the relay, but one of the relay signal contacts isn't making, n'est pas?.

[blugrassspecial]

Yes mechanically the button works well, it clicks into place very smoothly and without any resistence, again however it does not, I guess, connect to ALL the contacts inside and leaves the amp in limbo until returned to the out position. THE Question now is, one, is the AMP itself totally worth the cost of possibly reparing it? And two, has anyone done this repair and what was the cost ??
All in All it is a beautiful amp but only half of it works!!??

[Enzo]

Yes, in this case the switch only operates the relay, but until we consult schematics we could not make that assumption in general.

So you either have a bad relay - probably under $10 for the part - or something is wrong about that particular channel circuit.  In the channel you could have a bad transistor, a bad gain select switch, a bad control, a bad connection between any couple of things.  None of those parts are expensive either, leaving labor as your main repair expense.

The expensive parts of any repair would be the transformer and power transistors.  Yours work - the other channel proves that.

As to someone having seen this EXACT symptom AND having it be from the exact SAME cause, who knows.  As a professional tech, I am not going to waste the time to dig up sheets of possible repair scenarios when it is faster and more accurate to simply determine what is wrong and fix it.

In my shop I charge a one hour minimum for labor.  That is $60 here.   It is doubtful I would need more than an hour to fix this.  SO if you walked into my shop with $75, you would likely still have some left when you left with the repair.

[blugrassspecial]

Thanks for the info I'll start lookin for a repair shop and get some prices...

[Roly]

Thanks for the info I'll start lookin for a repair shop and get some prices...

Caution: repairs are normally quoted on the worst case possibility, so be sure to mention that it's confined to one channel and is working fine on the other.