TIMS showed Smoke External Alarm at car1553. Staff(YCK) checked and confirmed no signs of smoke / f ire / burning smell on exterior or interior of train. Rear T 207 line clear and confirmed no abnormalities. TIMS showed S ~~~~~ 1553 TIMS showed Smoke External Alarm. Staff(YCK) checked and confirmed no signs of smoke/fire/burning smell on exterior or interior of train. Rear T207 line clear and confirmed no abnormalities. CE : 1553 smoke external alarm reset ok n fault cleared.    Depot to follow up.  1553 FC 721. OPS 20 raised to replace smoke detector.  Celine Tan 45162   Follow up OPS 10. C/O #1553 external smoke detector. Vacuum and purge to drain water. Security amd function check done ok.  Leong / Hafiz.R 27.08.2023 #1553 smoke detector S/N: OLD: NIL NEW: KSFSD-06 Notif: 2518773