TC reported Front M1 'B3' train door didnot open. Staff (RFP) checked and confirmed Front M1 'B3' d oor did not open. Train was been escorted and stock change a t TLK. ~~~~~ #1604 DOOR LOCK MECHANISM STUCK DUE TO OUTER ROLLER WORN OUT LHS AND DOOR FULL WEIGHT APPLIED ON DOOR LOCK MECHANISM.C/O ROLLER AND FUNCTION TEST OK.OPEN/CLOSE SPEED/TIMING OK.GANESAN/TEH/LEONG/HAFIZ R 22.10.2023