TC reported TIMS showed smoke external alarm at car 3543. Staff(NEW) checked and confirmed no sign o f smoke at car 3543. ~~~~~ 3543 TC reported TIMS showed smoke external alarm. Staff(NEW) confirmed no sign of smoke at 3543.  3543 smoke alarm fault not duplicated in depot. Swapped fire control panel from #3543 to #1543. No fault was detected. OPS 20 raised to RSDBSD to check smoke detector. Fire Control Panel S/N : (after swapped) #3543 : 113 #1543 : 111  Jervis/Kana 44391 To replace 3543 smoke detector.  3543 transferred to RSDBSD for further rectification.  Kana 44391     #3543-#2 End smoke detector water ingress at PCB. Replace smoke detector,at fire control panel remove tag,normalise FDCB1 & 2.Cut out s/w normalise fire internal,pre external,smoke detector.Function test smoke detector ok. Done by Zulq/Saini/Haslan. 15/07/21