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.
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.
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.
It was a nice day, so I decided to take a pinball backplane, bottom board and bring it outside and dissect the basic components there and discuss how they work.
Ok, that’s a mouthful huh? This is a continuation of a previous series of videos I’ve done on fixing deep ruleset issues in EM games, and now that we’ve found what’s wrong, let’s fix it!
First, here’s a video on how to replace the latch relay – there’s another post where I demonstrate how to remove the backplane from the game so it’s easier to work on.
And in this next video, if you don’t have a replacement part, I show how with a little ingenuity and a #4 tap, you can fabricate your own roller for the articulating arm.
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.
The backplane (bottom panel) is typically held in place by a few specific things that need to be un-bolted before it can be removed: Several bolts on the panel itself, then some Jones plugs that attach to the wiring harness going to the playfield and backbox, then the power button, and finally, the board holding the tilt/plumb bob and Jones plug going to the coin door.The tilt board is removed with a few screws, then detach the coin door Jones plug.Also don’t forget the power cable has to go too, which may require unbolting the head to pull it through the inside.
This is a short video demonstrating a pinball head back cover I made with a piece of 3/8″ plywood. Very easy to make, and what I like about it, is the wood actually makes the sounds of bells in the head sound a little warmer and less loud, which I think works well in home environments.