When the hard disk drive ribbon cable is positioned correctly, the red wire on the cable is aligned with pin 1 on the drive connector. To identify pin 1, look for a 1 or 2 at the connector on the drive’s circuit board.
Make sure the holes in the cable connector fit over all the pins in the hard disk drive connector; then push in the cable connector.
3.Locate one of the power supply cables that lead from the power supply (behind the horizontal drive bays). The power supply cables may be secured in a plastic band on the side of the power supply. If so, unfasten the band to access the cables; you can use any one that is free. (If your drive requires a small power supply connector, use the smaller one.)