What was found
WHILE OPENING MAIN CABIN DOOR THE LEFT CONNECTING LINKAGE CAME APART. PARTS ARE ON THE COUNTER. CORRECTIVE ACTION: ACCESSED AIRCRAFT AND NOTED THE DOOR LINKAGE HARDWARE ON THE GALLEY COUNTY AS LEFT BY THE / CREW. TECHS NOTED THAT THE HARDWARE WAS MISSING THE REQUIRED RETAINING RING FOR INSTALLATION. CONTACTED MCC AND PLACED PARTS ON / ORDER. AWAITED PARTS. RECEIVED PARTS AND VERIFIED PAPERWORK. TECHS RECONNECTED THE MAIN ENTRY DOOR LIFT LINKAGE USING LEA NEW PIN P/N: 7411323-5 AND LEA NEW RETAINING RING P/N: MS16625-4031 IAW CE680A MM 52-15-15. PERFORMED THE CABIN DOOR OPERATIONAL CHECK WITH NO DISCREPANCIES NOTED IAW CE680 IVIM 52-10-00.