Definitely agree with liftmagnet; almost any issue with game reset will revolve around the AX relay and AX reset relay. If there's a constant clicking coming from the backbox or head then the AX relay contact is causing the player unit to cycle.
Something helpful I did when I first starting working with EM's was film the relay bank in the cabinet with my phone and watch frame by frame to determine whether the sequence was doing what it was supposed to. I wonder if seller would be willing, in which case you could post here and we could help you determine the issue against a good startup cycle.
O'fallon, MO
