TC reported Front DT car 'A1' train doordid not opened at SOM NB with obstacle detected. Fault did not recur at the next station. Staff(ORC) checked and confir med no abnormalities. TC reported Front DT car 'A1' train do ~~~~~ 3645 TC reported A1 train door did not opened at SOM NB with obstacle detected. Fault did not recur at the next station. Staff(ORC) checked and confirmed no abnormalities. Reported at SOM NB.  3645 A1 door performed the following checks : FOD found: N Weather strip condition ok: Y Roller condition ok: N, 3645 A1 RHS Outer Roller delam Clean J-rail & guide rail: Y Door cyclic test 20x, DIR extinguish ok: Y, after rectification TIMS door static timing test pass: Y, after rectification Door lock switch red line flush: Y Door close switch actuating plate distance ok: Y Replaced #3645 A1 door rollers to iron rollers.  Daniel/Chan SW/Redzwan 45498