TC reported smoke external at front DT car. Rear Train 409 rear train line clear from BDL NB to BSH NB, no abnormality. SM(AMK) checked and confirmed no abnorma lity. TC reported smoke external at front DT car. Rear Train ~~~~~ 3528 TC reported smoke external. Rear Train 409 rear train line clear from BDL NB to BSHNB, no abnormality. SM(AMK) checked and confirmed no abnormality. CE : 3528 smoke external alarm reset ok, no abnormality found.  3528 TIMS indicated FC721 (Smoke External Alarm). Fault self cleared. Swapped #3528 Fire Control Panel to #1528. Monitor/checked on TIMS, no fault indication found. OPS 20 raised to check smoke detector/plaseal.    Short loop to BSD.  Rajamohan/Fazly/Farid 45058 Fire Control Panel S/N : #3528 : 085 #1528 : 053 To check smoke detector and plaseal Check and found FSD sensor was old and dusty,no water seepage unto pcb ,Evap area no observed freon leak or water condensation.Only found alot RAD and evaporator over area,use compress air clean up ok.FSD c/o and function test ok. FSD:- Not: 2488283 RAISE. Done by Sanip/Koh.  13/05/23