As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#848, LAS-JFK. (ETOPS) 'CKPT TRIM VALVE ( COCKPIT/CABIN TRIM AIR VALVES ); REF TSM 21-63-00-810-852-A PERFORMED OPS TEST OF COCKPIT TEMPERATURE CONTROL AND CABIN TEMPERATURE CONTROL IAW AMM 21-63-00. OPS TEST OK. NO FURTHER TROUBLESHOOTING NECESSARY. A/C OK FOR SVC. MX-4 UPDATED PLACARD REMOVED.