The speech crackles now and then while background sound is fine. The board worked perfectly on the repairer's bench but crackled again back in the game.

Speech crackles even after a board repair: repin the driver board connectors

Cause: Poor contact in the two connectors on the right side of the solenoid driver board.

Checks

• Since the board works elsewhere, look at the game's connectors rather than the board.
• Check the speaker load: two 8 ohm speakers in parallel present 4 ohms, which some members warn can stress the amp.

Fix

• Repin those two connectors with new pins.

Systems

• Bally MPU AS-2518-35

Games

• Xenon

Related tips

• Sound Plus -56 and vocalizer test points
• Sounds Plus -56 and Vocalizer test points (Xenon)
• Xenon vocalizer: hot diodes, hum, or game will not run with it attached
• Background sound works in test but not in games: check DIPs 29-30, then reseat connectors
• Bench-test a -51/-56 sound board with a test EPROM
• Background sound disappears after the game has been on a while: sound setting
• Squawk and Talk: distorted sound or hum
• Spare sound board works on the bench but is silent in the game: no -5 V, bad 7905

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