Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Hi, I recently acquired the solid state Studio PA (seen here http://sunn.ampage.org/site/museum/studiopa/studiopas.jpg (http://sunn.ampage.org/site/museum/studiopa/studiopas.jpg)) and am having some troubles with it. It powers up and gives off a very loud 60 hz cycle hum. None of the pots effect the volume of the hum and no signal goes through over the hum. Does anyone have a schematic for this amp (or one similar), or can anyone point me in the right direction of what to start checking?

Appreciate any help,
hijdra

Check if the output transistors have blown.