What was found
MIGRATION/FAILURE OF SCREW IN GUIDE ARM ASSY, LT FORWARD ENTRY DOOR, THE FAILURE WAS IDENTIFIED BY GROUND SERVICE CREWS BEING UNABLE TO OPEN THE CABIN L1 DOOR, THE DOOR BECAME JAMMED & REQUIRED EXCESSIVE FORCE TO OPEN. INSPECTED DOOR HINGE AND ROLLER COMPONENTS. FOUND THE RADIUS LINK PIN RETENTION SCREW HEAD SHEARED AND JAMMING THE ROLLER CHANNEL. NO FURTHER DAMAGE FOUND. REPLACED THE RADIUS LINK PIN, WASHER, KEYWASHER AND RETENTION SCREW. TORQUED RETENTION SCREW TO 20 LBS/IN. DOOR OPS CHECK GOOD. IAW AMM 52-11-21 AND SB 737-52-1175.