I'm very near the end of a complete Gottlieb Haunted House restoration and I've run into an issue I can't resolve. Everything works - displays, sound, scoring...except solenoids. Basically no flippers, no slingshots - nothing solenoid controlled. I've traced it to the game over relay not engaging when a game is started, and if I hold in the relay manually all solenoids (pop bumpers/slingshots) work.

If I ground the Q1 transistor, the relay engages as it should. I originally thought the transistor was bad (tests good) or the driver board had an issue, so I swapped my Black Hole driver board but got the same result. I then swapped the BH MPU along with the driver board (changed the game ROM), but got the same result again. Self-test will activate the U relay but not the Tilt or Game Over relays. I can't figure out why the game over relay isn't latching when a game is started.

FYI - all ground mods completed.

TIA for any help.

Quick update on this issue:

I've tried every combination of driver board, mpu, interconnect from my working BH, but still have the same issue w/HH. Ball trough switch is registering. At this point, since all grounds appear good, I probably need to break out the logic probe to make sure the transistor is being fired on the driver board. I'll update when I have more info.

Problem Solved:

After taking every avenue to figure out the issue with my HH, it came down to having 2 pins crossed when I repinned the A2-J3 connector that attaches to the driver board.

Thanks to those that offered suggestions and hope this helps someone in the future.