TIMS showed Smoke External Alarm at car3524. Staff(BGB) checked and confirmed no signs of smoke on exterior or interior of train. Rear T235 line clear and conf irmed no abnormalities. ~~~~~ 3524 TIMS showed Smoke External Alarm. Staff(BGB) confirmed no signs of smoke on exterior or interior of train. Rear T235 line clear and confirmed no abnormalities. CE : Found 3524-Tims showing smoke external. Reset fault cleared. No abnormality found.  3524 Found FC 721 (smoke external) on TIMS. Checked #3524 external smoke detector. Found smoke detector gasket missing. Plaseal and cable gland in good condition. NO water or dust ingress found. Swapped SDR11 relay on fire control panel between #3524 and #1524 preventively. OPs 20 raised to replace external smoke detector.  Jonathan Koh 45176 3524 To C/O External smoke detector.  Found water ingress into external FSD. Replaced new external FSD Function tested satis. Plaseal and cable gland installed. Notification to CSC: 2524519 Done by Sanip, Rizman, Firas. 17/9/2023.