Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Hey,
   I'm pretty new to the world of amps and electronics. I just built a pickup for my banjo today, and got out an old fender frontman(the cheapest, simplest one) that my friend left here to try to fix it. I play guitar on Fender Deluxe but it gives me crazy feedback on my banjo. So, the problem with this frontman is when I plug in, all I get is a loud buzz sound which goes away when I touch any metal part of the instrument. However, I also get absolutely no input. I took the back and looked at the solder joints, and as far as I can tell they're all in order. Any advice or starting points? I've tried to find resources on solid-state repair and diagnosis but can find none. Any help would be greatly appreciated.

Will