TC reported train doors at front M1 carwere not proven closed. Opened and closed train doors once t o clear fault. Staff(CNG) monitored at platform and found noabnormality. ~~~~~ * ,N *    Checked all doors on 1537 and found A1 door having jumpy movement. Checked J-rail - no FOD.  Moved door manually to check further. Suspect LHS door leaf having delaminated roller. Checks done at siding. No platform to remove door leaf. OP20 for rectification. DONE BY: AZLI/HASZHAN 19.07.2023 * ,N * OP20: Found 1537 LHS leaf #2 roller and RHS leaf both rollers having indents. Replaced all 3 rollers and restored door leaves. Function tested ok. Cyclic test and 10/20mm door gauge test passed. DONE BY: LAI MK/ALI  20.07.2023