Posted a while back that I was having that “two balls kicking out into the shooter lane” issue. After re-soldering some lugs, playing with all the switches repeatedly, replacing a diode, and screwing around with it 4 or 5 times, I was directed to this thread:
Just fixed the issue. The trough kick up arm was moving kind of sluggishly, gummed up. Apparently, if it even takes an extra half second to reset to resting position, the stuck actuator tricks the CPU into thinking another ball is needed. Disassembled and cleaned it all out as others have said in that thread, and the issue was rectified.
So when everybody jumps to an opto issue, if you have this problem don’t be so quick. A simple cleaning the mech with isopropyl and a Q-tip and applying a bit of lube gel, and you’re back in business.
Took care of the credit dot, and she’s back up 100%.