I'm pulling my hair out here.

I've got a World Cup Soccer and a bunch of switches aren't working. IF I unplug J2 on the Opto Switch board (the one that sends +12v out), all the switches start working except for Column 4:
Screen Shot 2017-05-29 at 10.44.50 AM (resized).png

1) I've checked ALL the wires and no shorts and they are all soldered nicely.
2) I also put in a brand new PindoraBox.com opto board (with new chips) in and still no difference.
3) All the opto transmitters have +12v going to them (actually they read at +13.9v but that shouldn't be an issue right?)
4) Finally, I sent the CPU board in to be examined by none other than johnwartjr who gave it a clean bill of health.

What is going on? If one of the transmitters goes bad, does it take out a bunch of other switches? Is it possible that that's the issue? I'm going bonkers here.

Yeah, I'm wondering the same thing. Currently it's not working but it was a second ago. Weird. Whatever is shorted on that plug, it's taking out all of row 5.

I do but it was doing the same thing