Ah, but you are still using the original 5V circuitry for all of the chips on the Driver board, plus the chips on most of the other non-mpu boards. (although I think the sound board almost always generate their own 5V.)

But you are still correct. The real problem isn't with the 5V circuit it has always been a problem with how the reset circuit sees the 5Volts.

Wrong circuit. Color DMD and most of the mods pull from connectors J116-J118 and these supply 5V and Unregulated 12V, not the regulated 12V that goes to the MPU.

reading up on this I love this idea and can't believe someone didn't think of this sooner. How easy and cheap to pop one of these on, rather than spend an hour+ replacing $20 worth of parts on the driver board.

Bought the last one on the website. Still lists 7 more available on ebay.

see earlier in the post. This should work in every WPC generation from WPC (alphanumeric) Funhouse/Bride of Pinbot/Harley all the way up to WPC95 Cactus Canyon.

Finally tried one of these out in a Fishtales. It still reset during one ball play with no other games on. I'm guessing that I am probably looking at a broken diode on a coil/flipper or a bad coil bridge. Or more likely a switch matrix issue that caused a slam tilt.