I'd try to troubleshoot this issue as a 1 player game... We would need to find out what switches send power to the 10000 point score reel solenoid. The final switches in the circuit are the 1st "ten thousands" runout switch and the 9th position 1st "thousands" switch. Check these switches to make sure they are adjusted properly. Also, make sure the switch stack screws are tight and the switch stack lugs are not touching each other.