On my NBAFB, the GI string for the lowest part of the playfield (slingshots, inlanes...) seems locked on: It turns on immediately when the game powers up, and if I do the GI tests in the service menu, all the other strings will do the gradual dimming test, but this string stays on full strength throughout. If I play the game for ~5 minutes, the fuse for this GI string will blow.
I was originally checking for shorts when I had the issue with the fuse blowing (didn't find any), but now that I've noticed the "locked on" issue, that seems like it's indicating a different problem. Appreciate any insight you can share!