I may be completely off base, so at the very least consider this post a bump to get someone more experienced on the line. I have an 86 Gtb Genesis, and I had a slightly different issue with the GI flickering with the vibration of the pops. Turns out one of the rollover lane sockets had a bad connection, and just fiddling with the one wire caused flickering. Replaced the socket and lights work. There was no discernable break in the wires, only a bad connection.

I'll make a few assumptions here.

You've checked the bulbs-obviously.

You've checked all of your fuses and they are all working and the correct ratings.

Now some questions. Do you have the manual? Can you post some pictures of the both the top and bottom of the playfield with the power on? This would be particularly helpful, especially if you can do so during the lamp test portion of the machine's diagnostics, if it has them.

EE