TC reported smoke external at Front DT car. Staff(BBT) checked, no sign of smoke or fire found. RearT205 line clear towards BBT SB, feedback no abnormalities f ound. ~~~~~ TC reported smoke external at Front DT car. Staff(BBT) checked, no sign of smoke or fire found. Rear T205 line clear towards BBT SB, feedback no abnormalities found. CE: T205-3720 No Smoke External Found  Replaced #3720 smoke external detector. Added cable gland and security checked ok. No further abnormalities observed. Function checked ok. DOne by: Pravin/Fazil 45299