TC reported fire internal alarm at RearM1 car. Staff(AMK) checked and feedback no heat or smoke obs erved in train. ~~~~~ 1509 TC reported fire internal alarm. Staff (AMK) feedback no heat or smoke observed in train. CE: 1509 smoke external pre-alarm able to reset No abnormality  1509 FC 721 registered. Opr 20 raised for BSD to Follow Up Syahid 45041 1509 To check smoke detector and plaseal #1509-FC 720x1. #1509-#2 end RAD smoke detector no water ingress.For preventive measure c/o smoke detector unit. Function check unit ok.Monitor no occurance of fault.Check all car smoke detector #2 end ok,Plaseal added more done. #1509-Smoke Detector Unit: Not: 2482948 raise to CSC Done by Saini/Haikel.  26/04/23