As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW PERSONNEL REPORTED DURING PUSHBACK APU / RT PACK OPERATING. FA'S REPORTED AN ODOR OF BURNING PLASTIC. MAINTENANCE DEPARTMENT PERSONNEL REMOVED AND REPLACED BOTH COALESCER BAGS IAW AMM 21-20-02, RAN APU FOR SEVERAL MINUTES, NO SMOKE OR ODORS NOTED, AIRCRAFT OK FOR SERVICE.