One or more switches, or a whole group of switches, never register in switch test.

Dead switches from failed SIP resistor networks

Cause: A failed SIP (single in-line) resistor network on the switch matrix board.

Checks

• With power off, measure each resistor in the SIP networks on the switch matrix board against the value printed on the pack.
• Note which switch group is dead; it narrows the search to the networks serving that connector.

Fix

• Replace any SIP network that reads open or off value with one of the same value and pin count.

Systems

• Capcom

Related tips

• Prove whether dead switches are on the playfield or the switch board
• Reflowing surface-mount chips on the switch matrix board
• Erratic opto switches from cracked opto board joints
• Where the boards sit in a Capcom backbox
• Pinball Magic trunk keeps opening and multiball won't load

Source: Capcom Pinball Problems/Solutions