You likely have a failing power supply or have some broken legs on some of the mosfets, or possibly some failed rail capacitors. I would stop using the amp ASAP before you make the damage to it MUCH worse. Depending on what exactly is wrong with it the repair price on this amp could range anywhere from $100-$250, but yes we can repair it.
The board in this amp is just a bigger version of the same board that it's alot of other amps. Some of the Alphasonik amps, the Planet Audio, TT2250D P2250, VX2200D, the Power Acoustik A3000DB. Those amps all use a VERY similar board, but the board in the Opti 2000D has about 20%-30% more mosfets for about that much in power increase over those other models.
Chris
dB-r Electronics