I picked up my first Williams pin. My other three are all early Stern Electronics. I bought this pin brought it home and it sat for several weeks before I plugged it in and started it up. When I turn it on I get one of two different results. The back box and playfield lights come on in both cases. The only difference is sometimes the displays flash for a half second and go blank. The other result is the player one, nbr of games and ball in play displays come on and does a continuous loop with different numbers flashing. I've replaced the batteries and checked the fuses. Any suggestions would be greatly appreciated. P.S. I'm a pin repair newbie. Thank You.