TIMS showed Smoke External Alarm at car2536. Staff(BSH) checked and confirmed no signs of smoke ext erior or interior of train. Rear T412 line clear and confirm ed no abnormalities. ~~~~~ To check TIMS for FC and corresponding smoke ext (2535 or 2536)and reinstall SDR11 at 2536 Found no water ingress into PCB,C/O due to fault intermittent.Function test ok.#2535 FSD external fault plse refer to W/o: 11644701 #2536-FSD external:- Not: 2478087 Done by Sanip.  07/04/23 #2535 Smoke External Reset And monitored Ok. 45020