TIMS showed fire and smoke external alarm loss power at Front M2 car. Fault self cleared. TIMS showe d fire and smoke external alarm loss power at Front M2 car. Fault self cleared. ~~~~~ 2556 TIMS showed fire and smoke external alarm loss power. Fault self cleared. CE : Tims showed no fault. 2556 no abnormality found.  2556 FC: 735 (fire and smoke detector loss power). Replaced DC-DC converter & power supply unit. Function check ok.  Sarma/Shafie/Sugu/Alan/Lee PT/Anand/Kamarul 45322