What was found
LEFT PACK LIGHT IS ON WITHOUT MASTER CAUTION RECALL ACCOMPLISHED BITE OF PACK TEMP CONTROLLERS REF FIM 21-62 TASK 801. LEFT TEMP CONTROLLER FAULTING TCV. FOUND FAN BYPASS CHECK VALVE DOOR MISSING. REF FIM 21-53 TASK 820 FOUND BYPASS CHECK VALVE DOOR MISSING. REF LOG 7197306 FOR PDA LOGPAGE. ADDED MFG DDP C/W PER MEL. REMOVED AND REPLACED DIFFUSER ASSY PER AMM 21-51-03-400-804-002. OPS CHECK GOOD, NO LEAKS NO RECALL LIGHTS NOTED. ENSURE DISPATCH DEVIATION PROCEDURE IS REVERED BEFORE RETURNING THE AIRCRAFT TO SERVICE. PERFORMED PACK TEMPERATURE CONTROL - BITE PROCEDURE IAW FIM 21-62-801. NO FAULTS NOTED.