From memory....the bonus unit does indeed step up once. This is when I place it in the zero position, turn the machine on and then start a game....then I manually hit a few drop targets, the machine dings and the score reels spin, then the ball drains and it just sits on ball 1....
Excellent. Do the same thing but re-examine the zero position switch on the bonus unit. Wires red-black and green. This should close when the unit steps up. After that the only thing that can stop power going to the bonus relay is the out hole switch. Can you post a close up picture of the zero position switch of the bonus unit?
