As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VCS SYSTEM WAS FAILING AND HAD A ODOR IN THE CABIN. WHEN MAINTENANCE PERSONNEL TURNED ON VCS SYSTEM, IT WAS NOTED EXCESSIVE NOISE AND VIBRATION COMING FROM THE GROUND COOLING FAN. ALSO, NOTICED ELECTRICAL BURNING ODOR IN COCKPIT AND GROUND COOLING FAN INLET. INSTALLED REPLACEMENT GROUND COOLING FAN IAW AMM 21-23-05 AND SB 500-21-0008.