TC reported train doors at car 3646 didnot opened. Staff(AMK) checked and confirmed car 3646 'B4' d oor did not opened. Staff(AMK) later isolated the defective train door in closed position. TC reported train doors at ca ~~~~~ 3646 TC reported train doors did not opened. Staff(AMK) confirmed 3646 'B4' door did not opened. Staff(AMK) later isolated the defective train door in closed position.  3646 B1 door performed the following checks : FC 932 - saloon door B1 open operation time out. FOD found: N Weather strip condition ok: Y Roller condition : RHS outer roller delaminated. Replace all rollers to new type rollers. Clean J-rail & guide rail: Y Door cyclic test 20x, DIR extinguish ok: Y TIMS door static timing test pass: Y Door close switch actuating  ok: Y  Sarma/Lee PT/Kamarul/Shafie/Anand 45440