TC feedback TIMS showed train doors fault at car 2617'B2' door. Thereafter train tripped in AM whi le departing YCH2 with ATS alarm showed CBTC applied due to train door opened while moving. Staff (YCK) checked and feed ~~~~~ 3618 - TC feedback TIMS showed train doors fault at car 2617  'B2' door. Thereafter train tripped in AM while departing YCH2 with ATS alarm showed CBTC applied due to train door opened while moving. CE checked:2617 B2 door able to open and closed No abnormality.Depot pls check.  2617 B2 door found LHS & RHS outer rollers damaged. Replaced both LHS and RHS rollers with iron rollers. Function checked the doors are ok. Mating strip, push pull, DSS, DLS red line, DLS lock nut and top rubber ok. Cyclic and static test ok. Done by: Rizman/Sanip 45260