Train doors at Rear M1 car 'B4' door were not proven closed. TC recycled train doors a few times - o k. Staff(RFP) checked and confirmed no train doors abnormali ties. Fault did not recur at subsequent stations. Train door ~~~~~ Train doors at Rear M1 car 'B4' door wer L3   Found #1628-B4 door and #3627-A1 door both RHS inner roller declamination. Replaced to iron black roller and do all the criteria check and function door test. Done by Rizman/Sanip.  04/01/24