I have a hot tip I'm working on.
Currently I have a system 4 mpu in it. Rebuilt 40 pin and updated driver board.
It was working fine until it started a weird power up issue. When you turn it on it acts as if it's starting a game. Flippers work. You can't actually start a game.
After a while it will start doing its own thing.
I will make a video and link it in the comments.