300ex still won’t go

its been awhile and I’ve been busy with work and haven’t been riding lately but i need to fix my 300ex, I’m dying to get it going. I flipped the quad a couple months ago and it started right up but now it won’t start and none of the lights are on either, it seems like there isn’t even a battery connected. I tested the battery and its good, fuses are good, and i jumped the solenoid and it cranked over perfectly, but didnt start obviously because there is no spark, what could it be? someone had said it was a bad bank angle sensor but i don’t even think 300ex’s have bank angle sensors, i looked on the wiring diagram and looked them up and couldn’t find them. So what else could it be?