Separating and refitting the CPU and driver boards

Steps

• Remove all six screws on each board.
• Keep the CPU board in its tray while easing the driver board off the interboard pins; it flexes, so go gently.
• To refit, seat the CPU board in its tray and press the driver board on from left to right without forcing it.
• Fit at least two screws per board, then reconnect all plugs.

Systems

• Williams System 3
• Williams System 4
• Williams System 6 / 6A
• Williams System 7

Related tips

• Is it the CPU board or the driver board? Boot the CPU alone
• Replacing the 6802 CPU with a 6808
• Identifying a System 3 to 7 CPU board
• What changed on the System 6A CPU board
• System 6 CPU board test points
• System 7 CPU board test points
• System 6 CPU board jumpers J1 to J6
• A System 7 CPU board can run any System 3 to 7 game

Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part One, Clay Harrell (pinrepair.com)