Where the display high voltage enters and leaves the solenoid driver board
SDB connector J3 receives about 230 V DC from the power supply (pins 6 and 3, supply and its ground) and sends the regulated 190 V out to the displays on pin 8 (page 55).
Systems
Related tips
- Rebuild the solenoid driver board high-voltage section
- Set the display high voltage to about 170 V
- The solenoid driver board also carries the 190 V display supply
- Capacitor C26 holds the display high voltage after power-off
- All displays dark after fitting a new power supply: blown solenoid driver board fuse
- Power up and set a rebuilt high-voltage section
- High voltage still too high or too low after a rebuild
- No score displays light at all
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)