Ok this guy had this sitting around and needed it gone. I purchased it from him. It is a combo amp the speaker is good. When powered on I hear one bump from the speaker, plucking strings it doesn't say a word. I plugged in headphones plucking the E or A string I can hear very faintly that there is something there. I can't find a schematic on the net. I really need help. I am doing this as a confidence builder. What does the faint output from the headphones imply, if anything? I have the head out of the cab and a visual turned up nothing. Where should I start with this?