Train door at Front M2 'A1' door unableto close. Staff(ADM) unable to push close. Staff(ADM) feedba ck train door had a gap of one arm's length. Staff(ADM) feed back unable to isolate train door. Train was disembarked. TC ~~~~~ Train door at Front M2 'A1' door unable L3  Fault able to be duplicated in depot, 2647 A1 door was unable to be closed when commanded. TIMS showed FC 023: 2647 A1 close operation timeout (CLE) multiple triggers. Opened lintel cover and found DLD dislodged from the door operator, blocking the path of the door operator arm, preventing the doors from closing fully. Checked and found no other abnormalities, weather strip ok, carbody no rubbing marks, rollers in good condition, push/pull force 5-6kg. Reinstated DLD with mounting bolts torqued as per maintenance manual specification and torque-sealed. Checked door isolation device ok, able to isolate and normalise when fully closed. Checked all DLD mounting screws torque and applied torque seal. Door function test ok, door cyclic and static tests ok. DIRBS in both cabs normalised. Done by: Sateesh, Alauddin, Shah (01/12/23)