Pressing a flipper button resets the game, or a slingshot hit tilts it.

Flipper button resets the game or a slingshot tilts it

Cause: The flipper lane-change and slingshot switches are disturbing other matrix switches; here a bad 2N3904 column transistor and a bad SR15 column network.

Checks

• First check for missing, bad or miswired switch diodes.
• Then test the column transistors and SR15.

Fix

• Replace the bad 2N3904 and SR15.

Systems

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

Related tips

• Inlane, outlane and drain switches all dead: blown switch transistor Q49
• System 11 switch matrix: connectors and chips
• Switch matrix dead after an under-playfield adjustment with power on
• Row or column error: CPU board or playfield?
• Fixing a dead switch column on the CPU board
• Quick test of reset transistor Q1
• Testing the MPU reset circuit at U9 pin 40
• Single reset parts that hold the LED on

Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Three, Clay Harrell