What version game ROM do you have? I am confused...
Suffice it to say that my guess is that the current ROM does not have the knocker functionality. Anyone else like to comment on whether that is a possibility?
Of course, we could be barking up the wrong tree on this one.
In the interim, is there any chance of you tracing the violet and black wires from the coil back to the driver board, and checking continuity between the coil end and driver end of the wires (with the machine turned off)? (Assuming they are violet and black - that's what the manual said.)
Adjust multimeter to 200 ohms setting.
Place one probe end on the coil end where the violet wire attaches.
Place the other probe end on the driver board where the violet wire attaches.
You should see a zero reading.
Repeat for black wire.
