As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JUST PRIOR TO LEVEL-OFF FL370 GOT BURNING ODOR IN THE FLIGHT DECK. CABIN TEMP ROSE TO 80+ DEGREES. *S/D* LT ACM FAILED AND WAS REPLACED. AIRCRAFT WENT BACK TO REVENUE SERVICE WITHOUT FURTHER INCIDENT. THE BURNING ODOR WAS THE SMELL PRODUCED BY THE ACM AS IT SEIZED.