TC reported fire external at car 3512. Staff(RFP) checked no abnormalities. Rear T340 line clear fee dback no sign of smoke. TC reported fire external at car 351 2. Staff(RFP) checked no abnormalities. Rear T340 line clear ~~~~~ 3512 TC reported fire external. Staff(RFP) checked no abnormalities. Rear T340 line clear feedback no sign of smoke. CE : TIMS showed #3512 having Smoke External Checked there's NO abnormalities. Fault able to reset. No recurrence of fault during monitoring.  3512 TIMS showed FC 721 (Smoke External Fault). Checked & cleaned smoke detector & terminal box. Found terminal box rubber gland missing. Gasket checked/found still intact. . OPS 20 raised for external smoke detector c/o. .  Redzwan/Aliff/Daniel/Chan SW 45337 TWD: 3512 To replace External smoke detector   Checked 3512 smoke external unit found was new. Checked no dust, no rust, no abnormalities. Preventively cleaned with compressed air. Function test ok, no c/o deemed necessary. Done by: Sanip, Koh (1/3/24)