Hi, I am new to pinball machines. Recently was given a 1989 Williams Police Force. I have never seen it functional. It was extremely dirty, with cracked rubber, etc. I spent some time and cleaned it up and all of the mechanical components seem to be functioning well when running the onboard tests. The lights all seem to be functional. When I turn the machine on it goes into attract mode and the audio seems to work. However, when I hit the start button the machine pops a ball into the shooter lane, then promptly resets. From the reading I've done it sounds like it could be the 5v power supply. However, from what I have been able to find it doesn't seem like that is typically a consistent problem right at the game start. Before I start through the online checklist for 5v supply issues I am wondering if there is anything else I should be checking. Thanks!

It does still have the original battery holder, but there is no evidence of battery corrosion on the board.

Thank you very much. Reading through that did solve my problem. Luckily it was just the slam switch on the coin door. Easier fix then I could have hoped for.