I’ve run into this problem at least 3-4 times in the last month with different early Bally/Stern solid state games: The game boots and appears to work but you can’t start a game and/or many switches/buttons don’t seem to work? Before you dive deep, try this simple, easy trick.
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In this short video, I go over how to test the coin door service switches, and if faulty, how to replace them.
This is a fairly simple procedure.
If you have a button in the coin door that doesn’t appear to work, the first thing you should do is check to see if any of the wires have broken off or there’s a bad solder joint. This is very common because the coin door is opened and closed quite a lot and things can get snagged on the wires. Always check the wiring to make sure there are no kinks or damage to the wire. In the video I use a multimeter set to continuity to test the integrity of the switches. If the switches seem to work and the wiring is intact, the next thing to check is the continuity between the switches and the connector on the MPU board. If all that checks out, it could be one of the chips on the MPU board that handles the cabinet switches.
I had a chance to spend some time with a 70s era Gottlieb EM machine I recently picked up. This game came to me in non-working condition, mostly complete. For the complete video series with the early “first look” footage see this article.
In this series I spend most of my time diagnosing issues that are relating to the score reels. I also take some time cleaning various contacts and relays which end up solving a variety of problems from games that never end to problems properly scoring shots and bonuses. I hope you enjoy as I dive into this game getting it back to playing condition and learning along the way.