Studio PA troubleshooting

[hijdra]

Hi, I recently acquired the solid state Studio PA (seen here ) 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

[mckinnon audio]

   Hi there,sounds like you've got some bad caps (filters) in your power supply,could also be a bad ground somewhere in the audio path,but I'd check the filters first.Good luck,Mel.