Quoted from Quench:As a shortcut, the "Self Test" button on the Alltek MPU board is wired as an alternate coin door Self Test button. So you can use it to set the free game scores until you sort out the coin door button switch.
Notes on the coin door button switch:
The red wire goes to the MPU board J3 connector pin 1
The yellow-red wire goes to the solenoid driver board J2 connector pin 7 which is basically ground.
Im working on a Mousin today with the same issue.....Is the wiring the same?