Staff(TAP) feedback train door at car rear M2 "A3" door did not open. Staff(BSH) checked and confirm ed no abnormalities. CE check & feedback no abnormalities. ~~~~~ 2604 Staff(TAP) feedback A3 train door did not open. Staff(BSH) confirmed no abnormalities. CE feedback no abnormalities. CE: All doors proven open and closed no abnormality. Depot to check door function.  2604 no FC registered. Found #2604 A3 door rollers cracked - replaced all 4 rollers. Cleaned J-rail/guide rail & no FOD was found. Checked weather strip condition & door gap 64.1mm - OK. Door cyclic test & DIR able to extinguish. TIMS door static timing test - Passed.  Celine Tan 45065