Rotel amps have fuses inside. To take a look, unplug the unit and let it sit for awhile to ensure that the capacitors have time to discharge. I have read that one can get a shock if they have not. Take off the screws and take the top off. Look for the fuses and pull them and see if any have blown. Replacements can be bought at radio shack for a few bucks. I have done this with my RB991 without problems. If its not the fuses, you will have to have someone look at it.