I'm in need of a little help. I have a switch that is failed. It's the Ball Trough 1 switch. It fails to recognize the ball and because of that, the game will not start. I have tested the diode and switch. Both tested OK. No other switches are giving me problems. Searching though the forums, I found a post from 2 years ago discussing this problem. The suggestion was to check the connections in the head. No followups were posted. It looks like connector J9 on the interconnect board holds the wire for this switch. I disconnected and cleaned the pins. No obvious signs of problems there...

Do you folks have a suggestion on where I should look next? THANKS!