1976 Capt Fantastic - was working well but sat idle for a few weeks and now it powers on fine, push to add a credit and it cycles through the normal process of resetting the scores, adds a ball on the back glass but doesn't kick the ball out - can manually add to the score - all methods of scoring work and flippers work but ball never gets put into play. Last bit of work done on it was with the Game Over Interlock Relay. Everything still "looks" great - good contacts and all of that with the GOIR. Any suggestions on what to do to diagnose/fix?

Thanks for the help! The outhole relay does NOT fire with the credit button. I triggered it manually and the ball kicked out as expected. What should tell the outhole relay to fire?

FIXED!!!! Dirty contacts on the reset-relay. What an amazingly finicky machine. Thanks for pointing me in the right direction!