A rom could be bad and needs to be reflashed or replaced. You can always carefully reseat the eproms first to make sure because stress creep is always a possibility too. To be honest what I would do is just give the board a good washing in the dish washer. and let it air dry via a fan for a day or two. After that reseat the eproms and if you are still getting issues, then check all over the board to make sure there's no damage on any traces. As for the pot not working, you could snip the speaker wire leading to the jamma harness and try wiring a high watt resistor in there or something, and just make a switch to select between it and normal. Also, the pot on the board may be bad, so eventually you'd probably want to replace it anyway.
