Dell XPS 14 (L401X, Late 2010) - Manual (Page 105)

System Board 105
15 Replace the Mini-Card(s) (see "Replacing the Mini-Card(s)" on page 24).
16 Replace the memory module(s) (see "Replacing the Memory Module(s)"
on page 17).
17 Replace the battery (see "Replacing the Battery" on page 14).
18 Replace any blank or card you removed from the Media Card Reader slot.
CAUTION: Before turning on the computer, replace all screws and ensure that no
stray screws remain inside the computer. Failure to do so may result in damage to
the computer.
19 Turn on the computer.
NOTE: After you have replaced the system board, enter the computer Service Tag
into the BIOS of the replacement system board.
20 Enter the service tag (see "Entering the Service Tag in the BIOS" on
page 105).
Entering the Service Tag in the BIOS
1 Ensure that the AC adapter is plugged in and that the main battery is
installed properly.
2 Turn on the computer.
3 Press during POST to enter the system setup program.
4 Navigate to the security tab and enter the service tag in the Set Service Tag
field.