Hiya Guys, I need help to fix 2 small practice amps and a stereo amp which my brother and I broke while trying to shatter a glass with a software based tone generator. Yeah I know, pretty stupid, but we were drunk. Anyway they all now have the same problem, they just hum loudly when switched on. Adjusting volume makes no difference and guitar plugged in makes no sound. I am sure it is probably a simple problem and any help would be greatly appreciated. Thanks, Dave.