What kind of sound problems are you experiencing? Can you still hear the sound? Is there distortion or "static" in the sound? If you are handy with a soldering iron, I would try all of the basic stuff first. Replace the capacitors on the sound amp portion of the board. Then try replacing the amplifier IC's. Verify that the S and V roms are OK with a rom burner, or if you can't do that, run a rom test by holding down the test switch when turning on the game.