only white power chord should be connected , is your PC is new or old? , dou you have SATA harddisk ?, becouse SATA disk type of power cable is not sutaible to that , you need old type having 4 pins in that chord
that means , you have sata capable smps , so you need to get chord converter black flat port to normal ide type port , to connect , it may cost you to rs 10 , get it