I had this machine working a week ago, but a single contact that was supposed to be NC was not and caused almost a week of havoc. The problem was found deep inside the control motor stuff - "replay cam." A real pain to get access to adjust the contact leafs. I had to pull the unit out, but not as much as a problem as returning the unit back to where it belonged.
I also had a problem with shorted leafs (wiring end) on the top contacts associated with the shuffle motor cam -- caused by bumping into the ball return board when replacing the playflield.
So it now it is working consistently with just a few burned out lamps associated with the features. I also need to procure a coin lockout coil as the current one is open. I suspect that PBR may have something that will work.