Keep the backbox ground strap tight
A braided ground strap in the backbox, behind the backglass, fastens under a wing nut. If it is loose or off, some features may not work or work badly. From Firepower on there is also a white-with-red ground wire from the playfield that must be clamped under the same wing nut.
Systems
Related tips
- Features misbehave with the backbox ground strap loose
- Loose wire at the backbox ground braid screw is the MagnaSave ground
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Three, Clay Harrell (pinrepair.com)