Train doors at car 3603 "B1" were not proven closed. TC recycled train doors once - ok. Staff(CCK) c hecked and confirmed train door closed with 100mm gap, recyc le once - ok. Fault did not recur at subsequent stations. Tr ~~~~~ 3603 B1 Train doors were not proven closed. TC recycled train doors once - ok. Staff(CCK) checked and confirmed train door closed with 100mm gap, recycle once - ok. Fault did not recur at subsequent stations.  3603 B1 door fault unable to duplicate in depot. Checked/found door operator was replaced with new on 15/12/2023. Performed the following checks : 1) Check history DCP swapped before & date: NIL 2) Check fault code: FC 933 (B1 door close operation timeout) 3) Download ER: ER shows TC cycled door once to clear fault. 4) FOD found: N 5) Weather strip condition ok: Y 6) Removed door checked roller condition ok: Y (Door installed      with new iron rollers) 7) Clean J-rail & guide rail: Y 8) Push/pull door smooth & no wobble: Y 9) Door cyclic test 20x, DIR extinguish ok: Y 10) TIMS door static timing test pass: Y 11) Door lock switch red line flush with surface for positive        latching: Y 12) Door close switch actuating plate distance ok: Y 13) Door gap (criteria 63mm+1.5mm): Found out of criteria at         67mm, adjusted to 64mm. 14) Swap DCP if N  for monitoring: DCP swapped between B1 door      and A1 door for monitoring. #3603 DCP S/N B1 door: 1701W020071S026 A1 door: 1405W020041S005  Jonathan Koh 45288