So you were adjusting things with the game on? Yikes. You could've sent high voltage down low voltage logic circuits. Have you read the pin wiki on WPC games? I'd start there.

I wish I could offer more advice. Good luck.

Hey Walt, did you replace the fuse and are all the LEDs on the power driver on?

Does the CPU boot with just connector j210 connected, nothing else? If not, swap the CPU chip 6809 with one out of another game.

Not the room, the CPU chip

Also, try firmly pressing on U9, best to do this with the board out and laying flat.
CPU (resized).png

J210 is all that is needed to see if the board boots. Any of the switch matrix cables at the bottom of the board will not matter if connected or not. You definitely want the ribbon cable disconnected until the board boots because other boards connected via ribbon cable can also keep a game from booting, including the ribbon cables themselves.

Definitely ask for NVRAM to be installed as well. It is great having a large collection that is battery free.

Could have been two problems. CPU not seated properly and something with the sound board. If you disconnect the sound board does it boot up?

Likely one of the chips on the sound board pulling down an address or data line. If you have a logic probe you could narrow the issue down to which address/data line. After that you've typically got to cut traces to identify the specific chip.

Also I would pull the cpu again and carefully inspect the socket (corrosion, bent pins, etc.) to help make sure that issue doesn't return.

So you're just removing the ribbon connector at the sound board?

I'm lost here. Is J202 the connector you're removing and then the game boots?

Reseat the 4 connector ribbon cable from the CPU to fliptronix to sound board to the DMD controller board. This is the one I see act up most often.

Ribbon cable reseating (resized).jpg

I was hoping the ribbon cable was the original problem. I agree on replacing it soon. Fixed just in time for the holiday weekend. Enjoy!!