So my sega was acting up,where as when it came to me to start 2nd ball the ball wouldn't eject from the ball trough. I tracked the problem down to the receiver opto. If I pushed on a certain part of it ball would pop up like normal and work for awhile.
I ordered a new receiver opto. When I plug it in it says 2 balls are in when none are. When I align it where it's suppose to go the transmitter shines on it but says balls are still there. No matter what I do it does not recognized that balls are not there. If I start a game it says to many balls even if the correct amount are installed. Is this a case of the new opto being bad? If I plug in old opto balls register switch 14 15 just like new opto but goes away when I align it....with no balls in trough. Thanks for any help.

I've heard this also, almost bought both when ordering and wayout thanks for the link.