All controlled (matrix) lamps are out, but GI works.
No lamp matrix lamps light
Cause: No +18 V lamp supply (fuse F114 or bridge BR1), or failed U9 or U18 on the driver board. Rarely the transformer's 18 V winding.
Checks
- Check LED6 on the driver board.
- If LED6 is off, check F114 and BR1.
- If LED6 is on, check U9 and U18 outputs for pulses.
- Check the +18 V wire is intact.
Fix
- Replace the fuse, bridge or chip found bad.
Systems
Related tips
- All matrix lamps stay on
- How the WPC lamp matrix works
- None of the controlled lamps work, or they light in the wrong pattern
- How the WPC lamp matrix is switched
- How the lamp matrix drives a bulb
- WPC lamp matrix and GI driver parts
- Lamp matrix fuse F114 (F106 on WPC-95) keeps blowing
- Driver board LED6 off (+18 V lamp matrix)
Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part One, Clay Harrell (pinrepair.com)