I know the SAD 4096, which seems impossible to find, is usually the culprit but the game manual says to change the LM 3900's, the 4066 and 4065 also. I was wondering if anyone had one of these resolve the problem. My board did work a few years ago but it quit. I have a repro on the way but I would still be thrilled if I could fix this one. A search on the SAD 4096 pulls up a bunch of people with guitar re-verb units looking for them as well.