Train doors at rear M2 car 'B2' doors were not proven closed. TC recycled train doors a few times - ok. Fault did not recur at subsequent stations. ~~~~~ Train doors at rear M2 car 'B2' doors we     Chek and found B2 left hand side door outer main roller damage.Change out ok.Door mating strip/push pull/DLD/DLS/DSS check ok.Door cyclic and static test ok. Done by Sanip. 02/06/22