As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BETWEEN 16000 AND 24000 FEET HAD A HARD TIME REGULATING CABIN TEMPERATURE. ONE PACK HAD ALREADY BEEN PUT ON MEL, EMERGENCY WAS DELCARED AND AIRCRAFT RETURNED TO BLOCK. AIRCRAFT LANDED WITHOUT INCIDENT. NO OVERWEIGHT LANDING. CHANGED EQUIPMENT AND REDEPARTED. REPLACED FLOW CONTROL CARD PER AMM 21-51-09PB401. AIRCRAFT WAS GROUNDED.