I am having some issues with ball trough for Dungeons and Dragons. Game plays with 3 balls in trough as it should, but every time I put fourth ball in trough it kicks two out at a time during gameplay or start of game. I have done all in Clays guide, reflowed all solder points, tested resistors, etc. etc. Even covered ball trough with blinds so no stray lights were effecting the leds.

During test mode, ball trough shows ball right, ball mid, and ball left. Unsure what to do next. I know there is a new set of boards out there, but didn't want to go there yet since these should easily be repairable, not much to them.

any tips appreciated.