Yes, opening and closing the door several times and duct tape on the cash box door took care of the problems. I am able to play the game and all looks good. In a while I am going to re-enable the bill accepter and see about that.
There is one problem I found now that I can play it, when I get the 'Wild Times' symbol on the center reel, it makes the excitement sound but never enables the top box game. At first I thought maybe because because I was only playing one coin so I played 3 coins until I got the symbol again and, although it had the happy sound when the reel stopped, no top game play.
The 2 pin connector is not used for your version of your hopper. Check for bent pins on the hopper electrical mating connector on the backside, which connects when you slide the hopper in.
Open and close the door 3-4 times to clear the errors.
Make sure the toggle switch labeled coin mech on the front of the MPU is in the up position.
52 is Bill acceptor cash box door not fully closed