Quoted from PhillyBilly:
Having inconsistent ball launches again. Seems to rattle when it drops downs from the launch trail right at the video lights. Also its doesn’t happen often but it’ll drain my multiballs and I’m back down to one ball and end my game. Any thoughts?
An issue with the mist optos or opto board can potentially be a cause for ending multiball early, or an issue with the ball trough (not sure if this comes up at times with the castle lock opto or not as well). Do you ever have issue with the mist function? You may be able to test it by turning the mist/magnet feature off and see if it stops having that issue, or do a switch test for the trough.
Also, if the game ever spits out two balls without multiball, the arm sometimes needs to be adjusted for the shooter lane VUK.
On my game, it was the left/receiver opto that went bad and ended multiballs early (and did so gradually/intermittently for a long time before completely failing).