If you unplug the coils again (how it was before), does switch row 4 start working again? If so, is there any sort of under-playfield circuit board that those systems connect to? My guess is that the coils were disconnected for a reason.

I haven’t been able to find a schematic for that opto board, but from a web search it appears that only has four optos. If that board was the issue I’d think only four switches would not be working, but you report more than that as having issues.

Have you verified that you have proper power voltage at the opto board? Is there a game-specific test for hulk motor/switches that you’ve tried? If you remove the opto board and interrupt the optos with a business card or similar do any register?