What was found
UNCONTROLLABLE FLT DECK TEMP. ONLY HOT. ONLY COOLED W/LT PACK OF F. DEBRIEF FROM CA, FLIGHT DECK TEMPERATURE HOT WITH LT & RT PACKS ON, LT AIR MIX VALVE GAUGE READING RIGHT ABOVE HALF ON HOT SIDE, PERFORMED AUTO & MANUAL CONTROL INPUTS WITH NO CHANGE IN TEMP, PLACED LT PACK SWITCH TO OFF, FLIGHT DECK TEMP COOLED OFF, MOVE TEAM HOOKED UP TO AIRCAFT, NOT ABLE TO BITE TEST. DEBRIEF FROM CA, FLIGHT DECK TEMP HOT WITH LT & RT PACKS ON, LEFT AIR MIX VALVE GAUGE READING RIGHT ABOVE HALF ON THE HOT SIDE, PERFORMED AUTO & MANUAL CONTROL INPUTS WITH NO CHANGE IN TEMP, PLACED LT PACK SWITCH TO OFF, FLIGHT DECK TEMPERTURE COOLED OFF, MOVE TEAM HOOKED UP TO AIRCAFT, NOT ABLE TO BITE TEST. LOCKED BY TOMC FOLLOWED FIM 21-61 TASK 844. R & R AIR MIX VALVE IAW AMM 21-61-02-400-801. OPS CHK GOOD. NO FAULTS NOTED AT THIS TIME.