Hi guys, Not sure where to post this exactly so will start here. My brother-in-law knows I fix old PC's so has presented me with an "opportunity" to fix one of his mate's old guitar amps which recently stopped working. Details are scarce but from what I'm told they were messing around with the voltage selector around the time it stopped working - why anyone would do that is beyond me but there you have it. So it powers up - lights come on and I can here very low static from the speaker. I've tried some basic things like checking the fuses (all look good), plugging in a speaker to the external speaker out, tapping things randomly with a screwdriver (you never know your luck). The caps look good too BTW. So there's life in it, but the level of static doesn't change at all when you crank up either of the volume knobs - actually none of the knobs have any impact on the static, and I'd expect these 40 year old pots to have some crackle in them at least. And there's zero crackle when you plug things into the input jacks - I don't have an electric guitar but have tried a microphone and my iphone playing tunes. Any thoughts? My totally noob guess is that they've partially killed the PSU with their dicking around with the voltage selector - again, WTF would you touch that? Pic attached if that helps.