Quoted from Jamesays:power on backbox lit but no tilt is not on.
pushing start powers up playfield lights,resets target reels and kicks ball to plunger but no ball 1 lights up
It sounds like one of three things to me. Either the trough switch is dirty or not making when the ball rolls over it, or the outhole is kicking the ball to the shooter lane early, before the score reels reset.
If it’s the latter, then after the first ball you shoot into the dead playfield drains, the next ball kicked to the shooter lane should register Ball 1 and the game should play.
If it’s the former, then you you just need to check the trough switch and clean it and make sure it’s gapped properly.
Lastly, if it’s neither of those 2 things, then you need to check the Ball Count Unit to see if it’s resetting and stepping like it should.
Check the first two and if they are not the solution, then we can diagnose the Ball Count unit.