Ok so I have an egnater rebel 20 head and matching cab, that I like very much. Been working fine...played it earlier in the week with no problem, then plugged in yesterday, and nothing no sound...checked the speaker cab with another amp, and its not the cab or speaker cable...no matter what output i try, no luck out of the head....any thoughts on first place to look for an easy fix? could it be a fuse issue? I don't really know much on tube amp repair, so any tips would be great....everything lights up ok as far as the power light. thanks,