Dell Vostro 400 (Mid 2007) - Manual (Page 131)

Removing and Installing Parts
131
6 Replace and tighten the four screws to secure the hard drive.
7 Connect the power and data cables to the drive.
8 Connect the data cable to the system board.
9 Check all cables to be certain that they are properly connected and firmly
seated.
10 Replace the computer cover (see "Replacing the Computer Cover" on
page 166).
NOTICE:
To connect a network cable, first plug the cable into the network port or
device and then plug it into the computer.
1 hard drive 2 power cable 3 serial ATA data cable
4 system board
connector 5 screws (4) 6 screw holes in the hard
drive bay (4)
2
4
3
1 5
6