Dell XPS 12 (9Q23, Late 2012) - Manual (Page 9)

After Working Inside Your Computer
After you complete replacement procedures, ensure the following:
• Replace all screws and ensure that no stray screws remain inside your computer.
• Connect any external devices, cables, cards, and any other part(s) you removed
before working on your computer.
• Connect your computer and all attached devices to their electrical outlets.
CAUTION: Before turning on your computer, replace all screws and ensure
that no stray screws remain inside the computer. Failure to do so may damage
your computer.
• Turn on your computer.
After Working Inside Your Computer | 9