TC reported Front DT A2 door did not open SM MRB confirmed train door did not open a MRB SB. SM MRB isolated Front Dt A2 door at MSP SB. Staff(RFP) help to past ed sticker. ~~~~~ 3613 TC reported A2 door did not open. SM MRB confirmed train door did not open a MRB SB. SM MRB isolated 3613 A2 door at MSP SB. Staff (RFP) help to pasted sticker.  613/614 ER & Fault Trace D/L & found no door related FC. Cycled doors & found doors able to open & close. Checked/found 3613 A2 LHS door outer roller delaminated, FOD on J-rail & RHS door outer roller damaged. OPS 20 raised to replace rollers.  Celine Tan 45035 To changeout rollers.  3613 A2 door RHS & LHS outer rollers delaminated. Found RHS inner roller stiff & LHS inner roller bearing loose. Replaced all outer/inner rollers. Performed door cyclic test - OK. Door open/close timing within criteria, door gap = 63.5mm, weather strip condition - OK. Cleaned J-rail/guide rail & no FOD found.  Anand/Sarma/Alan/Shafie/Sugu 45035