My TOM has been acting up lately and I'm about out of ideas. My trunk tests fine, but it goes to the wrong position for multiball. Also, it will randomly give me credit for locking the first ball. The second ball locks fine but it won't start multiball like it's supposed to (even though that guy says MULTIBALLLLLL).

Recently I had display issues that turned out to be U4 on the MPU. Removing and reseating fixed the issue.

So far, I've replaced all the ribbon cables, added the aluminum opto-interruptor, taken the trunk apart, cleaned, reassembled, removed and re-seated all associated connectors under the playfield and on the boards, re-seated the ASIC. I've also replaced the game and sound ROMs. The only thing left I can think of is having the MPU rebuilt.

Please help!

.....and I re-flowed every flipping pin on the driver board.

Yes, it was broken. However I installed the metal one, it worked for just a game or two and started acting up again. I checked the board and it’s tight, but that sure would make sense. I disabled the trunk motor and played a couple games and the game was fine. Seems like it’s something to do with the trunk.

This is a HUO game. It’s got some plays on it but not a ton.

To be clear I changed the opto-interruptor before I posted. It’s still acting up. I just tried a game with the trunk enabled and nothing has changed. Even though it tests fine, maybe a new trunk opto board?

Turned out subway opto #36 had become misaligned and was closing randomly when the game was moved or solenoids fired.

The other issues were the ASIC chip. I bought a NOS one from Pinball Life and that took care of all the other crazy issues.