Upon powering up the game, my Bally Vector Solenoid relay starts clicking and the light flashes. It stops when you hit the start button but during game play many of the insert lights don't work. The game plays fine and all solenoids work as they should. Seems to just be the insert lighting that's affected. Any advice on how to troubleshoot? I looked under the playfield and tried to see if anything was shorting anything but couldn't find anything. Thanks! Here's a video of what it's doing upon power-up.

Thanks! I'll give that a try. I just got the game and haven't yet got all the issues worked out. It does sometimes drop some of the X,Y, or Z drop targets when it serves up the ball which is odd. Playfield insert lights were working until the solenoid driver relay issue started. Could just be a coincidence as it doesn't make sense that they would be related like you said.

I got the problem figured out. It was all due to the connectors on the lamp board. I reseated them and got the rest of my missing insert lights back. And also the solenoid expander clicking issue went away. Must have something to due with how the expander board is driven off the lamp board? I'll have to reflow all the pins on the lamp and re-do the connectors as they seem flaky as they are.

My only remaining issue now is that the game will usually auto-drop one of the X,Y,Z drop targets whenever a ball is kicked into the shooter lane. My guess is that if i take care of my connectors on the lamp and MPU board that hopefully that will go away as well. thanks for your help!