I have a ‘66 Chicago Coin Hula Hula (2 player) that is exhibiting issues with the player unit. After starting a new single player game, the first ball will play and score under Player 1. However, balls 2-5 will randomly be played and scored under either Player 1 or Player 2. There does not seem to be any noticeable pattern. Additionally, sometimes the ball count will not advance to the next ball after it was played. If I start a 2 Player game, the symptoms are the same.
The ball count and player unit step up and reset okay manually. They also seem to step up and reset okay during game play as long as they are getting the signal to do so, which does not appear to be consistently happening.
I have a schematic. Any ideas on typical causes?