I have a Disco Fever exhibiting some weird behavior. It boots and plays fine, but occasionally when it boots up the 1st player display shows 2 zeros and the ball in play display continuously counts up from 1 through 40 or so. Almost like it is in self test? If I turn it off and on, it will usually boot up and play fine except when the high score to date lights up, the 1st player will go blank and display nothing at all. The game will still play normally though. If I turn it off and on a few times, it will eventually go back to normal and display the correct pre-set high score to date. It never actually loses its memory permanently.
I replaced the 5101 and it seemed to fix it for a few days, but the problem is back again. I checked battery voltages with power on and off and they seem correct so I don't think the diode is shorted. Any other ideas?