The black wires that are strung together across the five solenoids are the constant “supply” voltage. Should be approximately 43 volts dc. The other wire connected to solenoid , each of which has an individual color code, I term the “control” wire And they individually go back to the solenoid driver board. The control wires are what energize the solenoid. When the solenoid is in the de energized position ( shelf state), the control wires do not go to ground. At this point there should approximately 43 volts dc across the individual solenoid terminals. When the solenoid is to be energized , the control wire goes to ground via the transistors on the solenoid driver board. There is now a current path from the constant supply voltage wires , thru the solenoid coil, thru the control wire , to ground via the solenoid driver card. The solenoid should “fire” and reset the target.

There are three possible problems. No constant voltage , burnt up solenoid coils and no ground path.

You need a multi meter and a jumper wire to trouble shoot.

1) with the game turned on, carefully see if you have 43 volts dc across the terminals of the individual coils with the multi meter. Touch the red multi meter test probe to the supply terminal and touch the black test probe to the control terminal . Since all 5 do not work, most likely all 5 either have or do not have the 43 volts. If no voltage. , need to trace back and find were the disconnect could be. Could be a connector , broken wire, bad board connection, or a board supply problem.

2). If you have the 43 Volts to each coil, Then the supply is good. I would next try to fire each coil. Take the jumper wire and touch the terminal the control wire is attached to ( do not touch the supply voltage terminal) with one end of the jumper wire . Quickly touch the other end of the jumper wire to a known ground. If the solenoid is good, the solenoid will fire. If the solenoid is bad, then nothing will happen. Nothing happens. Need to order new solenoids. If solenoids work, then for some reason the solenoid control wires are not going to ground. I would check the connector at the solenoid driver board or could be problems with the board itself.

Re reading your post. The five solenoids with the five black wires tied together have one source of supply voltage. The two solenoids that you do have firing have a different source. As I recall the , the source voltage for the two solenoids is the same same source as the two larger solenoids that reset the entire 7 drop targets via the mechanical reset. You can tell by the same wire colors on all four. For what it is worth the two solenoids that you do have firing have two diodes per solenoid coil. Versus the other five only have one diode per solenoid coil.

Since all 5 do not work, I agree, most likely a common connection issue. My last game however, all 5 did not work because some of the five black supply wires rubbed against the control wire terminals and lost insulation. Went to ground and the solenoid coils ( or diodes I guess) were failed. Had to order ew coils