Dignosing and fixing a dead WPC MPU board (with RAM upgrade)

In this video series, I am working on a client’s “Dr. Who” pinball machine that wouldn’t boot up. It was just dead. None of the diagnostic LED blinks would blink on the WPC-89 MPU board, so I go over the process of how to identify and isolate the problem, then I upgrade the board with NVRAM (non-volatile memory) so that it will never need batteries again.

This is an unedited series of videos showcasing some experiments I have been doing trying to repair damaged pinball ramps for which there are no replacements available at the present time. In this case, I’m working on a Bally Party Zone ramp, using different types of epoxies, plastics and adhesives. See work works and what doesn’t. In the end, I figured a creative approach using laser cut plexiglass tabs which were attached to ramps using two different types of adhesives.

Pinball Flipper Tune-Up: replacing bushings

If you have a wobbly-feeling pinball flipper, there’s a good chance the bushing is either worn or broken. In this two-part video I go over how to remove the flipper assembly and replace the bushings so you can get nice, snappy, flipper action.

This general technique applies to most flipper assemblies with only a few minor detail changes. Some bushings were screwed into the flipper assembly (especially with Gottliebs) and others were connect to the flipper assembly plates themselves (as in later WPC games).

Repair, don’t replace that broken pinball coil!

Pinball coils (aka solenoids) are windings of insulated copper wire that create electromagnets that make things move on the playfield. If you have a coil that is no longer working, and doesn’t have any obvious signs it has “melted down”, there’s a very good chance you can repair it instead of replacing it. In this video I go over how this is typically done. This works on all types of pinball machines from the EMs to Stern, Bally, Williams, etc.

Diagnosing, repairing and replacing pinball coin door service buttons

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.