Switch stacks are the primary parts of electro-mechanical pinball machines, triggering game activity. I go over in this video, how they work, the different types of switch configurations, and how to clean and maintain them so they work reliably.
Sometimes when you have to do more extensive work to relays in an old electro-mechanical game, you can’t bend over the cabinet. You need to get all those assemblies on a bench to service. I go over how you can remove the insides of a game so you can more easily access the components.
Here’s an overview of a few basic repairs I made to a game that has been working for awhile, then started to malfunction and then sat for awhile. After some time going over all the game problems I do a summary of what I noticed and fixed.