Go in the back and make sure the selection unit especially and timer unit reset and step up. Make sure that the timer cams and replay cams spin freely. No the pins aren't used for ground, they are used to align the " C, R, and D " buttons. This website has alot of information and if you e-mail him, he is also quite knowledgeable. http://bingo.cdyn.com/machines/bally/dixieland/