As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TURNING ON THE NR 1 PACK THE CREW NOTED A ODOR SIMILAR TO MELTING PLASTIC. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE NR 1 AIR CYCLE MACHINE TO BE THE SOURCE OF THE ODOR. THE AIR CYCLE MACHINE WAS REPLACED, OPERATIONAL CHECKS WERE PERFORMED AND THE DISCREPANCY WAS CLEARED.