Quoted from Quench:
You have an issue with the SDB not receiving the PB0 signal on J4 pin 6 which is one of the binary (lowest bit) momentary solenoid select signals.
Recheck that you have zero ohms continuity between MPU J4 pin 4 and the SDB on pin 23 of U2 (via SDB J4 pin 6).
I also hade the same issue with a Harlem Globetrotters and this thread helped me! It was the female at sdb J4 pin 6 that hade to be repinned with new female connector!