Did you check to see if all of your board connectors are properly seated? They can get yanked on during a move and fail later. Sounds like it wants to work, but they just won't reset after they are all knocked down? I would clean the switch contacts on the drop mech too if you haven't done so yet.

I wish I could be of more help to ya, all I got is these 2 last bits. Try googling "bally drop targets not resetting" or a few different things like that. Even if it is a different Bally game, the hits might be useful reads. My last thought is re-pinning as many IDC connectors to the MPU and power supply board as you can. I did a bunch on my Vector when I had one and it increased it's reliability a bunch. Good luck!