What was found
(CAN) ACFT WAS DISPATCHED WITH PACK 2 INOPERATIVE. AFTER DEPARTURE THE TEMPERATURE WAS AT 30C AND UNCONTROLLABLE. CREW ELECTED TO RETURN TO DEPARTURE AIRPORT. IAW T/S ACTION. PRSOV TRIM AIR VALVE, LT REPLACED IAW AMM 21-61-06. LEAK AND FUNCTIONAL CHKS OF THE VALVE CHECKS SERVICE. INTERCHANGED PACK TEMP CONTROLLERS FOR T/S IAW AMM 21-51-14. FAULTS. CARRIED OUT TEST OF CABIN ZONE TEMP CONTROL IAW AMM SUBTASK 21-61-00-725-081. CHECKED SERVICE TEST CARRIED OUT WITH APU AND BOTH ENGINES OPERATING.