As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING SHUTDOWN, PILOT REPORTED AN UNFAMILIAR METALLIC NOISE FOLLOWED SHORTLY BY ILLUMINATION OF THE COMBINING GEARBOX CHIP LIGHT. INSPECTION OF THE CHIP PLUG REVEALED METAL PARTICLES IN EXCESS OF ALLOWABLE, ACFT GROUNDED. COMBINING GEARBOX IS APPROXIMATELY 5.0 TSO.