Check with the guy. Big difference between 5 volts DC at a board and 6 volts AC at GI. Depending on what he put in there it may matter.
Quoted from mickthepin:
hey seem to back up in the ball popper to the upper playfield and the thing is trying to pop up 2 or three balls at once and can't handle the weight of it. Do any of you guys know anything about this problem???
Check the up kicker for worn or broken/cracked coil sleeve, see if the plastic part the ball rests on and gets kicked from, has any of the 4 fins broken off.
LTG : )™