Quoted from Bob59:I do have a multimeter and jumper wires. If that wire is just associated with the lights I'll fix that later. I was thinking it had something to do with the bonus because when I noticed this the bonus stepper would not reset it just kept going I needed to shut the machine off to make it stop.
I did check the m/B switch again and it looks like they are opening and closing as they should.
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Nice, clean, bonus unit! The rotor and rivet plate can also carry some extra ball/special/points features, but it shouldn't affect the countdown.
At what point did the bonus stepper start failing to reset? Is that a new issue?
I'm confused why the M/B switch is allowing the ball to kick out when the O relay path portion of the switch should be open at this point. If it is shorted somehow, it *will* kick the ball out though. You should measure the resistance of each switch path. With the power off, measure the resistance of both legs of the M/B switch when there is zero bonus on the unit and when there is non-zero bonus. Closed should generally measure 0.2 ohms or less, open will usually be more than 2-5 ohms (depending on the resistance of other sneak paths, thru coils, etc.). Also look closely at the solder tabs on that switch when you are taking the measurements, no shorts there?
Another thing you could do is to observe the actions of the Q and O relays during an active game. With the playfield up and a game started, rack up some bonus and then close the ball return switch - does Q move at all or does O fire immediately?