No the coil doesn't knock when connected. The board simply detects that the coil is locked on so it shuts all the coils down.
According to the manual for the Pascal board this is the process for the coil test on startup (and what I believe is happening on my game):
Moreover, the PI-1 X4 board makes an electrical test of the current that flows thru coils #6, 7, 8, ‘OUTHOLE’ and 'KNOCKER', to make sure that each coil and its associated driver transistor are working well. At power-up, the name of each tested coil is briefly displayed. In case of trouble, the coil protection relay shuts all coils down, the relay status LED is unlit, and an error message is displayed along with the problem source.So it sounds like it could be a driver transistor on the board? Maybe the driver transistor was stuffed from the outset since I was always getting that message from the very first time I ever booted the game up (even before I swapped the wires to the coil
).
