TIMS showed train doors at front M1 carA1 door did not open. Staff(CTH) checked and confirmed frontM1 car A1 door did not open. Staff(ORC) assisted to paste s ticker on the affected train doors. ~~~~~ 1616 TIMS showed A1 train door did not open. Staff(CTH) confirmed 1616 car A1 door did not open. Staff(ORC)assisted to paste sticker on the affected train doors.  1616 A1 door checked/found LHS door was faulty. No platform was available to further check on door rollers. OPS 20 raise to follow-up.  Sarma/Alan/Lee PT/Kamarul/Shafie    45081  1616 A1 door found LHS outer roller delaminated & replaced with new roller. Security/function check - OK. Cleaned J-rail/guide rail & no FOD was detected. Checked weather strip condition, door gap 63.8mm, door static test & door push/pull no wobbling - OK. Door cyclic test 20x & DIR extinguished when doors were closed.  Shafie/Sugu/Kamarul 45082