I have a new ST that has an eternal ball trough jam registering. In the switch test, it says "trough jam" and all the switches are listed as closed resulting in the machine forever firing the trough coil to kick out balls. This is a follow up issue after the original issue of node board #8 failing during the middle of a game. I verified that node board #8 was no longer working after isolating that from everything else. I swapped out the same board from my JP Pro and everything appeared to boot up fine and work, but then as soon as I started a game, the machine ejected every ball and kept firing the ball trough eject coil.

The opto boards appear to be working fine on their own, each opto blinks as a ball is dropped into the trough etc, but the diagnostic switch test says "trough jam" and all switches are registering as closed. Not sure what is making the switches show as closed. :/

any help on how I can narrow this down to what the real cause is?

yep, all clear.

Good question, I'll have to look closer, I didn't think to check the lights closely, seemed like everything was fine, but I'll try swapping the Trough boards and will double check the others, thanks

Thanks everyone, turns out the opto boards were fried as well. I replaced them with boards from my deadpool and everything is working fine.