Train doors at the Front M2 car were notproven closed due to pax was stuck in between the train doo rs and HHPSDs. Train doors were not able to close fully afte rwards. TC opened and closed a few times but to no avail. SM ~~~~~ Check and found #2639-A4 door isolation device faulty. Further check found metal plate bend which cause door unable to fully close. Replaced and function test door open & close ok. Door cycle and static test ok. Mating strip & push/pull resistance within criteria. Door locking device- Old: C151BL56051. New: C151BL84010. Not: 2267710 raised. Done by Sanip/Faddzal/Deeshan/Koh. 16/04/21. Suspect Door Isolation Device was damaged when staff attempted to isolate train doors when doors were not fully closed. L3 ER Download. 2639 A4 door FC 083/084/086. PTU Side door monitor show Heavy failure status(Status monitor) Check 2639 A4 door not able to close door fully, left 50mm gap. Try push close door to no avail. Push open door no issue. Check guide rail no sign of FOD. Remove Left/Right Door connecting plate. Manual Push open/close Left and right door ok. Able to close/open fully. Check door operator manual push open ok. Manual pushed close, unable to close fully. Suspect door operator having issue, unable to close fully. Zulq/lincoln. 15/04/21.