As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL350 APPROX 45 MINS INTO FLIGHTS A CHEMICAL / BURINING SMELL ISOLATING PACK DID NOT ELEMINATE ODOR EMER RETURN-PERFORMED TROUBLESHOOTING FOR CABIN ODOR IAW TSM 5-50-00-810-831-A FOUND WATER COMPRESSOR-AIR OVERHEATED. PERFORMED DECOUNTAMINATION IAW AMM 21-00-00. A/C OK FOR SVC.