What was found
MAIN CABIN DOOR WILL NOT SECURE CLOSED FROM EITHER INSIDE CABIN OR OUTSIDE AIRCRAFT. DOOR LOCKING MECHANISM SEAMS OUT OF RIG. REMOVED MAIN CABIN DOOR SIDE PANELS & STAIRS TO GAIN ACCESS TO CABIN DOOR HANDLE MECHANISM AND ADJACENT LATCH/LOCK SYSTEM. NO DEFECTS NOTED OF THE OF RIGGING OR MECHM HARDWARE, WHILE PAX DOOR WAS DOWN, ABLE PULL THE LEVER AND EXTEND THE LATCH PINS. NOTED SEVERAL OF LATCH PINS WERE FAIRLY DIRTY. CLEANED ALL LATCH PINS & THEIR RECESSES & PERFORMED OPS CHECK OF THE LATCH MECHSM. LATCH PINS EXTEND/RETRACT AS NORMAL. PERFORMED SEVERAL OPS CHKS OF THE MAIN DOOR, MAIN DOOR OPENS/CLOSES AND LATCHES PROPERLY FROM BOTH THE INSIDE AND OUTSIDE OF AIRCRAFT. IAW AMM 52-10-00. OPS CHKD GOOD