TIMS showed Smoke External Alarm at car3539. Staff(YCK) checked and confirmed no signs of smoke / f ire / burning smell on exterior of train. Rear T208 line cle ar and confirmed no abnormalities. TIMS showed Smoke Externa ~~~~~ BSD: 3539 Terminal gasket C/O 3539 TIMS showed Smoke External Alarm. Staff(YCK) checked and confirmed no signs of smoke/fire/burning smell on exterior of train. Rear T208 line clear and confirmed no abnormalities. CE: 3539 Smoke External Alarm Reset.Fault Cleared.  3539 FC: 721 (smoke external) Checked cable gland ok, replaced plaseal, clean smoke detector. No sign of water leakage. Terminal side gasket missing, Function check ok. OPS 20 raised to replace terminal gasket. Sarma/Sugu/Alan/Shafie    45315