Guys, this could be as easy as the stepper being out of alignment.

Make sure the Bakelite square, as shown in the bonus unit diagram above, is aligned squarely with the metal frame.

As a new EM guy myself, I was trying all kinds of adjustments with the arms etc, when someone showed me this trick. If you are in under the pf, it is easy to knock these out of alignment and it will screw up your resets and scoring.

rufessor - glad to know you are around. I have one of these too and have learned a lot already. If this is the most complicated one out there, then MagicMaco and I should be an EM geniuses soon.

I had a similar issue with the swiper unit yesterday. Magi, if you haven't figured it out already - you adjust the brass wire can manually operate the reset coil and the advance coil at the same time to simulate a reset signal.

I was having an issue where sometimes the left bonus would advance twice. After fiddling around for a long time i determined the rubber on the left stand up was too tight and would close more than once. I evened out the rubber and adjusted the switch.

Now the only issue I have is the top kicker advances the bonus twice, for which either side is activated. This is consistent. I haven't dug into that one yet, but it is probably a switch adjustment too.

This is a very popular game in my basement.