At game start the game plays a harsh 'broken glass' sound and the background sound is missing; all other sounds are right. It began as an intermittent fault after the game had been on for a while.

Garbled sound at game start and no background sound: driver board header joints

Cause: Cracked solder joints on the driver board header pins carrying one of the sound select lines.

Checks

• With the game on, ground each sound select transistor on the driver board in turn and listen for each sound.
• Wiggle the connector on the select line that misbehaves: if the sound comes and goes, it's the joint.

Fix

• Reflow the driver board header pins, then leave the game running a couple of hours to confirm.

Systems

• Williams System 4

Games

• Flash

Related tips

• Wrong sounds play
• Sound test fine but many game sounds missing: a sound line stuck on
• Missing words or sounds from cracked connector pins
• How System 3-6 games trigger sounds
• Use the solenoid test to check the sound lines
• Quick sound checks by grounding
• Solenoid fuse blows at power-on and solenoids fire: driver board logic chips
• Solenoid fuse blows at power-on: frayed 28 V wire touching ground under the playfield

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