Having problems with an amp I borrowed from a friend and I figure I'd better fix it before returning it to him Yes, I know there are a lot of threads about this that talk about the circuit that won't allow it to come out of standby if the main voltage is too low, but I think I may have a different problem. I haven't checked the main voltage in the place yet, but I don't think this is the problem because I've used the amp in this room plenty of times. The reason I say this is because this amp was working perfectly, then I went to connect it in the studio with an unfamiliar speaker cable, and into the "top 4" input on my ampeg 8x10 instead of the full 8 that I usually use. BOOM! a little smoke out of the back of the amp and blew the main fuse. I replaced the fuse and it now turns on, but won't come out of standby. Took the back panel off and all the tubes look fine. Any suggestions? Really need to take care of this before returning the amp and I'm hoping I won't need to take it in! I'm pretty handy, but not sure how to diagnose this. THANKS!!