Might be a stab in the dark - But check all Slam/Bounce Switches (CAB,BACKBOX,PF and COIN DOOR) -If they are supposed to be closed,clean contacts,if supposed to be open(Slide a piece of plastic over them) and finally check the Ball outhole contacts arent too close.
All quick checks but eliminate them as I spent 1 week solving resetting and dead machine symptoms  and these buggers were the culprit. 
And remember dont give up, leave it for a day or so and try again.
Kev