So I got a project whirlwind and it’s pretty much together. I’ve had an issue with the top drop target which I’m pretty sure is some kind of wiring issue. So I’m test mode initially the top drop would register but it would go crazy by repeatedly triggering and in gameplay would do nothing. I re soldered the opto legs and the connector pin legs and now it’s staying on steady in test. However when triggered during gameplay nothing happens until all 3 of the targets on the feel the power drop targets have been hit at which point it will give the award for both the 3 bank and the single drop and they will both then reset. Where is a good place to look for the issue? All of these targets share the same (yellow-green) column. Should I be checking for a row wire or maybe even a diode on the 3 bank board?

Does this sound more like a diode issue or a wiring issue? It seems unlikely a diode would break on the board but I can see one maybe breaking on the standup directly before the top drop target. This would make me think all the switches in the column would have issues though. Would a downstream diode cause an upstream switch to have no reaction until all 3 of those switches were triggered?

Bump: any Switch matrix experts to maybe lead me in the right direction? I haven’t seen how the two drop target banks interact in test mode but in test, the upper target registers correctly, in gameplay it will not register or reset until the 3 bank target has been dropped at which point the game awards points and or extra ball for the upper target register and then they both reset. Not at exactly same time it’s independent coil firing but very close together

... anyone have any idea? At least able to confirm if it’s a row short or a diode issue? I’m leaning towards diode because the switch is registering properly in test but only registers in game once all 3 switches in the 3 bank are knocked down.

Ended up being a flakey opto. Replaced and fixed