You're going to have to try. Usually schematics lump all like-switches together in the same place on the schematic (I think. It's been a while since I've looked at my gtb schematics).

You should try to locate a 100 point switch or two on the schematics, and follow the wiring on the paper until you see the point where they all the other 100 point switches intersect. That'll most likely be a point of interest for you to find in your game. If it isn't a relay issue, you might just have a broken wire, or a cold solder joint someplace. If you're having trouble reading it, take a detailed picture and post it here (wait. Maybe not. Would that be a Gottlieb copyright violation?)

Anyway, If I were a betting man, I'd say your problem is staring right at you. You just haven't looked at it yet.

Good Luck!

I believe you can post snippets of Gott schematics. but mbaumle is correct, the switches will be tied together, and tied to the transformer return "prob yellow wire"
Both the black and the yellow will connect via a jones plug to the head,
put a jumper on the yellow return line, then touch to the non black side of the 100 point coil, it shud fire.
then touch a 100 point switch, it may need to be closed but it shud fire the coil. if not, chk the connections from the play field to the head.

Sounds like like Xerico and a NorthStar I restored for him... "Hey the kickout holes arnt working", 3 days latter, 'duh, forgot about the pf jones plug".

I just sold a Magnotron and knew exactly what the problem was when I read it...because the same thing happened to me

Glad you found that little Jones plug...it's an easy one to miss.