So to be honest, I'm very new at this whole circuitry thing. I'm learning but my knowledge isn't quite up to par yet. I have a Randall RH 100 amp being run through a b-52 cab with four speakers rated at 8 ohms (if that matters) My head has stopped working. Initially I got a squealing when I plugged in my guitar but now I get absolutely no sound from it. The power light is on, but I have no sound. What could possibly be wrong?