Using the System 11 switch tests

Steps

• Switch edges: roll a ball over each switch; the display shows the name and number of the last switch closed. No reading or a wrong number means a fault.
• Switch levels: remove all balls and raise all drop targets. The display should then show no closed switches.
• Any switch still shown closed should be checked to see if it really is closed.
• Close one switch at a time; if others show as well, check the CPU/driver board.

Systems

• Williams System 11
• Williams System 11A
• Williams System 11B
• Williams System 11C

Related tips

• Entering the System 11 switch tests
• System 11 switch matrix: connectors and chips
• How System 11 switch numbers map to rows and columns
• A bad SR14 can short switch rows on System 11A and later
• Matrix fault remains with a good CPU board
• How the Williams switch matrix is scanned
• Use the switch matrix table in the manual
• "Check Switch ##" message

Source: Pinball Machines: How They Work & Troubleshooting, Norbert Snicer