Station staff (SBW) reported train doors#19 did not fully opened. TC confirmed no fault shown from his driving cab. Staff (KRJ) checked and confirmed Rear M1 c ar 'B2' door unable to open fully. ~~~~~ 1612 Station staff (SBW) reported train doors #19 did not fully opened. TC confirmed no fault shown from his driving cab. Staff (KRJ) confirmed 1612 B2 door unable to open fully.  1612 B2 door found LHS door roller came off & stuck in between outer & inner rollers causing door unable to open fully. Further checked/found RHS door outer roller having abnormal noise. Replaced all the 4 big rollers. Function check door operation & cyclic test - OK. Door gap 63.5mm, cleaned J-rail/guide rail, weather strip condition, Door open/close timing - OK. All doors were proven fully opened & closed. No DIR lit up when doors were closed.  Sarma/Sugu/Kamarul 45030