Hello all, When I start a 1 player 3-ball or 5 ball game, the backbox indicates 3rd or 5th ball. When I drain 1st ball it stays on 3rd ball but now scores for player 4. It then switches back and forth scoring for player 1 then 4 and seemingly never ends. I do not have a schematic and this is a first time repair on EM. I've been through about 100 different titles of SS machines and think I can fix this with your help. Thank you in advance for taking the time to respond.