What was found
CREW REPORTED THAT THE ACFT COMPLETELY LOSS PRESSURIZATION NEAR THE TOP OF DESCENT. PASSENGER OXYGEN MASKS DID DEPLOYED AND AN EMERGENCY DESCENT TO 10K WAS DECLARED AND EXECUTED. MX FOUND CABIN PRESSURE CONTROLLER NR 2, LT PACK FLOW CONTROL VALVE, LT TRIM VALVE, AND LT PACK TEMPERATURE CONTROL ALL TO BE BAD AND THEY WERE ALL REPLACED. THE RT PILOT REGULATOR VALVE WAS ALSO REPLACED. OPS CHECKS WERE NORMAL AND THE ACFT HAS RETURNED TO SERVICE.