ATS showed train did not depart after dwell time up. TC feedback TIMS showed Front DT car "A3" doorswere not proven closed and had recycled doors once but to n o avail. Staff(LKS) assisted to push close "A3" doors for tr ~~~~~ Fault unable to duplicate in depot TIMS shows 3643 A3 door close operation timeout: CLE (FC063)x1 during fault reported timing. ER shows DIR remain lit, TC cycled door 3x to no avail. Found 3643 A3 LHS door roller not rolling smoothly with rubbing marks. Push/pull test - 8Nm Checked found no signs of FOD at door guide rail. Distance between DCS and actuating plate satis. DIR and DMI able to light/extinguish during door cyclic test. Door operation open/close satis. Checked door weather mating strips with no rubbing marks observed, within criteria. Replaced 3643 A3 LHS door rollers. Performed Push/Pull test - satis (4Nm). Performed door cyclic test - ok, DIR and DMI able to light/extinguish. All doors timing were within criteria. Check both sides DIRBS sealed. Side finding found 3643 A2 LHS rollers with rubbing marks - replaced. Function test - ok N.A/kumar/rawi/29.01.23