TIMS showed smoke external at car 2668.Staff (TLK) checked no sign of heat or smoke on exterior or interior of train. Rear train T306 feedback no abnormalities . ~~~~~ Checked and observed smoke detector sign of water ingress. Replaced smoke detector. Security and function checked ok. Apply plaseal to prevent water ingress.  Akhbar / Surendar / Sridhar / Firdaus 07.09.2023 Smoke detector S/N: OLD:   NEW: