Quoted from coz6:I really struggled with this in my No Fear, even the plastic for the Through did not do the trick but in fact it was a gravity feed issue, Had to re-level the game just right to get it to work and still was only 75% of the time. To test the theory I would bang the game to get the third to feed and see if your all good then tinker away
ok i have found that when the machine wants to give you only 2 balls for multiball, i give the machine a good shake and then the 3rd ball will shoot up from the trough into the shooter lane. (as most machines do for multiball)
those optos are tested and working. maybe there is a burr in the tough and the ball is not getting all the way to the opto? maybe the shake is what gets it to the opto? so maybe the trough plastic will help this afterall?