T210(3645) reported front DT car A2 doornot proven closed. TC recycled a few times to no avail. Sta ff(ADM) boarded train and train doors were proven closed sub sequently. Staff(ADM) escorted T210 and feedback front DT A2 ~~~~~ T210(3645) reported front DT car A2 door L3  #3645 FC 043 CLE A2 door Open Close speed pass: Yes FOD found: No Door cycle 20x: Yes Rubbing marks: No Door Push/Pull force: Satis Door mating gap: Satis Door Lock Switch red line when door closed ok. Door Lock Switch Cushion Rubber intact: Yes Door Close Switch distance from actuating plate within criteria. Door Wobble: No Rectification Actions: Doors were able to cycle without any abnormalities after normalised. No scratch marks were found on the guide rail. Postulate FOD caused the door to be stuck, and subsequently dislodged when TC cycled doors. From the fault trace, the gap gradually became bigger and then smaller. Cycled doors 20x ok. Door operation was smooth. Checked and ensure guide rail is free of any FOD. Preventively serviced both J-Rail and guide rail. Door push/pull resistance ok. DIR and DMI able to light and extinguish accordingly. Door static test satis, open close timing within criteria. Preventively swapped DCP from 3645 A2 door to 3645 B2 door. Done by: Koh, Sanip, Jack (3.6.24)