My right kicker coil on my System 11 Road Kings locks on when I enter test mode, as well as when the game is started or any time power gets to the coil.
I got this Road Kings in 2015 that had been left in a bowling alley that closed after a flood in 1991. I've been working on it off and on since then. I refurbed it and got it working well and cleaned up except for this one problem. I Replaced the Q71 transistor. Problem recurred. Sent the board out for repair, came back with a clean bill of health, and problem recurred. Tried replacing Q71 again, still locks on. I've replaced the coil. I've traced both the power and return wire, can't find any issues.
Nobody makes an early System 11 replacement board and mine looks better than the "tested" ones I see for sale at shows.
I'm proud of my refurb efforts and the game is actually pretty fun to play, but this coil issue is ruining my accomplishment! I'm at the point now where I'm ready to remove the coil and just play with a dead bumper unless you guys have any ideas.