What was found
FWD SUPPLY DUCT INTERMITTENTLY, UNCONTROLLABLE TEMPERATURE VARIES FROM 16-60 DEGREE C. F/A REPORTED TEMP FLUCTUATIONS IN CABIN. ACFT GROUNDED. RAN PACKS FOR 45 MINUTES, WAS ABLE TO VERIFY FWD SUPPLY DUCT TEMP FLUCTUATES. BITE TEST BOTH CONTROLLERS NR 2 SHOWS "TCV" FAULT RT SIDE. REF FIM 21-61, TASK 864, FIN 21-62 TASK 801. FWD CABIN FROM ROW 15 FORWARD WAS NOTICEABLY HOTTER WHEN ABLE TO DUPLICATE HIGH END FAILURE. REPLACED NR 2 PACK TEMP CONTROL VALVE, REF AMM 21-51-10, OPS AND LEAK CHECK GOOD.