Quoted from terryb:
Check the spring on the right gate. Also check if the gate is bent outwards, which most of them are, the ball can fall into a position where the opto isn't blocked and the game loses the mist ball.
Thanks, Terry. I am assuming if the gate is bent outwards, the ball can roll forward enough to trick the game into thinking the ball is not in the gated area, and it instinctively thinks the ball is not there and opens the gate to "restock" the mist ball?
Before I saw your suggestion, I took the Fliptronics II board out, cleaned all female pins associated with the right gate (J907 and J903), re-flowed the solder on all the pins, put deoxit on each pin, put di-electric grease on each pin, and torqued all the mounted bolts down good (ensuring good grounds). I also re-slowed the solder joints for the 2 wires to the solenoid responsible for the opening and closing of the gate. No effect.
I also noticed that in the magnet test as the ball rolls from the left gate to the right gate, the right gate sporadically opens up and down in a VERY weak manner....BUT during the game the gate works perfectly.
I am sure the two problems are connected to the same fault.....
I'll check the gate bar's orientation and spring next. Should the gate be REALLY strong, weak or "mid-strength" ?