The chimes give a dead thud instead of a clear ring.

Chimes sound dull or muffled

Cause: The rubber grommets or spacers the chime bars sit on have hardened or crumbled.

Checks

• Look at the grommets on the chime unit mounts.

Fix

• Replace them with hardware-store grommets or small used rubber rings.

Systems

• Electro-mechanical

Source: Pinball Machine Care & Maintenance, Bernard B. Kamoroff (Bell Springs Pinball Alley)