channel 2 dies after a few seconds

[newmanm]

I have an eighties Fender solid state amp. channel one works fine. when I switch to channel 2 it starts to distort and then dies after maybe ten seconds. the volume fades very quickly.

I'm thinking it's one of the capacitors. there are two big electrolytics on the board.

how do I go about troubleshooting this?

[Nigel Goodwin]

For a start, post the model number so we can check the circuit.

There really can't be very much wrong, as only small parts of the circuit are different.

[Enzo]

I'd be thinking you have an open something rather than a cap. Like an unterminated input pin of some chip, and it works until the pin gathers up enough charge to shut itself off.