Repairing/Replacing a Stern/Bally Power Supply/Rectifier Board

As part of the ongoing restoration of a 1979 Stern “Trident” pinball machine, here’s a series of videos outlining how to replace the rectifier board on these games. This varies a bit between Stern and Bally due to wire color codes. References are here.

Source: PinWiki

EM Pinball 101: Strange Buzz and Scoring Problems?

This is a common problem that happens with old electro-mechanical pinball machines. One minute it’s playing fine, then the next there’s a loud buzz and/or the scoring runs continuously or doesn’t score properly. What’s the deal with that? I’m going to show you one of the most common causes.