As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD SOUND AND VIBRATION HEARD AND FELT UNDER COCKPIT FLOOR, FOLLOWED BY FAINT ELECTRICAL ODOR. MAINTENANCE FOUND AVIONICS BLOWER FAN 20HQ GOUGED ON THE INSIDE. REPLACED FAN IAW AMM 21-26-51. ACCOMPLISHED SATISFACTORY OPERATIONAL CHECK. AIRCRAFT WAS GROUNDED.