Quoted from Richthofen:turned on my Taxi pinball machine after a few days of it being dormant. No displays but GI comes on. Pull the backglass, none of the main board LEDs are lit at all. no controlled lamps. Where's the best place to start?
Mine did exactly that, it was the power driver board (I think that's what it's called? No electronics expertise). Swapping in a known working board would test...pretty sure Earthshaker would work but clear that with someone more knowledgeable than me.