First, check the fuse. You may need a magnifying glass or an ohmmeter to check it. If the fuse is bad, replace it.
If the fuse is OK,or you've replaced it, I'd suggest you take it to a pro audio service center for repair. This sounds like either a major power supply problem, or a shorted component, anywhere in the unit. It may not be cheap, but get a repair estimate so you can decide if it is worth repairing.
Answers & Comments
First, check the fuse. You may need a magnifying glass or an ohmmeter to check it. If the fuse is bad, replace it.
If the fuse is OK,or you've replaced it, I'd suggest you take it to a pro audio service center for repair. This sounds like either a major power supply problem, or a shorted component, anywhere in the unit. It may not be cheap, but get a repair estimate so you can decide if it is worth repairing.