Did you ever figure out the issue to this? I am currently having the same issue. This is what I checked so far:

- The coil stepper motors are off, the jaw works fine
- The head freely rotates when I move it and registers the left/right optos.
- Fuses F709/F714 are fine.
- J100 / J102 are firmly seated.

My start button is not lit. Interesting.

Can you clarify which plug you had to check? All mine seem well connected under the playfield.

Thanks. I reseated J109 and nothing has changed. The shaker motor works (which is on the same plug) but the start led and smaug coil steppers do not work. I have been tracing the connections back to J100 (on the smaug controller board) and cannot seem to continuity with the voltage line. I am going to keep at this a bit longer and then contact JJP if I can't sort it out.

Thanks Yfichelle and Rondogg! I basically reseated every connector on the board and pushed all connectors on the inside/outside of the PC case and Smaug now rotates back and forth with no issues.

I still have this start button light that is out...I swapped bulbs but that isn't it... hmmm.