TC reported smoke external at Rear DT car. Staff(YCK) checked no sign of smoke exterior of the train . Rear T231 line clear no abnormalities. TC reported smoke e xternal at car 3676. Staff(YCK) checked no sign of smoke ext ~~~~~ 3676 TC reported smoke external. Staff(YCK) checked no sign of smoke exterior of the train. Rear T231 line clear no abnormalities. Staff(YCK) checked no sign of smoke. CE : 3676 smoke alarm done reset. No sign of smoke/heat.  3676 Smoke External FC 721. Smoke detector checked/found LED indication 'Amber' instead of green. No fault indication in TIMS & FCP. SDR11 relay swopped on 30/12/2023 & 8/12/2023. Both dates with FC 721. Operation-20 raise for External Smoke Detector changeout.  Redzwan/Aliff/Daniel    45302 BSD: 3676 - Evaporator External Smoke Detector C/O