As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT THE CREW REPORTED THAT THE CABIN COOLING PAC BEGAN TO BLOW SMOKE AND EXPELLING HOT AIR. THE CREW DEACTIVATED THE CABIN PAC AND THE SMOKE AND HOT AIR SUBSIDED. TROUBLESHOOTING DETERMINED THAT THE AFT ACM WAS DEFECTIVE AND WAS REPLACED WITH AN OVERHAULED UNIT. OPERATIONAL CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE.