Dell XPS 730 (Late 2008) - Manual (Page 106)

106 System Setup
Dell™ XPS™ 730
Dell™ XPS™ 730X
7 Place the jumper on pins 1 and 2 and wait for 5 seconds.
8 Move the jumper back onto pins 2 and 3.
9 Close the computer cover (see "Replacing the Computer Cover" on
page 17).
10 Connect your computer and devices to electrical outlets, and then turn
them on.