The game starts making odd, wrong-sounding effects and call-outs out of the blue. Fresh ROMs for the CPU and sound boards make no difference.

Sounds suddenly come out wrong even with new ROMs: bad ribbon cable

Cause: A faulty ribbon cable.

Checks

• Reseat the ribbon cables between the boards and look for damaged or loose connectors; try a known good cable.

Fix

• Replace the bad ribbon cable.

Systems

• Data East CPU Version 3

Games

• Tales from the Crypt

Related tips

• Speech distorted or wrong and sound cuts out: leaked C30 corroded the voice ROM
• Check the sound board's regulated -5 V and +5 V
• Sound board versions are not interchangeable
• The 520-5050-00 sound board variant
• Data East and Sega sound boards by game
• No sound at all: check the -5 V regulator
• Loud hum from the speakers
• Sound board power input connector CN2

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