TC reported after changing end that fireinternal alarm in car 3541. TC reset - ok and confirmed no sign of heat or smoke. ~~~~~ CAR 3541 FIRE INTERAL ALARM U BLE TO DUPLICATE FAULT.CHECK NO 1 AND 2 END SMOKE DETECTOR CONNECTOR FOR LOOSENESS OK.WIRE OXIDATION CHECK OK.SMOKE DETECTOR TEST OK.PREVENTIVE MEASURE CLEAN BOTH NO 1 AND 2 SMOKE DETECTOR.MONITOR FOR 2 HOURS OK.TO BE MONITOR FURTHER ON MAINLINE SERVICE.SHAFIAN/RAM 14.10.2022