Well, this is the first time I've heard about checking the metal tab, so thanks to both of the prior posters for bringing it to my attention. I'm assuming it's the tab with the blue square on it in the pics. In the coil test, if I push Sparky backwards the coil works and shakes him. Otherwise nothing happens in the coil test if I don't touch anything.
How does this need to be adjusted then? Sucks not having service rails so the playfield can be slid out further to easier access.