As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED LT AIR CONDITIONING PACK LOW FLOW INDICATION AND ZERO PRESSURIZATION. RT PACK INOPERATIVE. RETURNED TO DEPARTURE AND LANDED WITHOUT INCIDENT. REPLACED LT AND RT AIR CYCLE MACHINE (ACM). SYSTEM GROUND CHECKED NORMAL OPERATION.