The game powers on, takes credits, starts and serves a ball, but no playfield switch scores. Only some of the switches show about 5 V on their input side.

Game starts but no playfield switch registers: failed 6821 at IC2 on the MPU

Cause: These boards don't use a switch matrix: each switch pulls its own MPU input to ground. A failed 6821 at IC2 had killed the inputs, so the problem was on the board, not the wiring.

Checks

• Look for stuck-closed switches first.
• Check continuity from the switch ground back to the MPU's filter capacitor ground.
• Jumper a dead switch input to ground: if it still doesn't register, the fault is on the MPU side.
• Check the 5 V across the MPU filter capacitor and reseat the MPU edge connectors.

Fix

• Replace the 6821 at IC2 on the MPU.

Games

• Getaway

Source: Pinball Repair help group!! (Facebook group)