Dell OptiPlex FN389 Quick Reference Manual page 15

CAUTION:
To guard against electrical shock, always unplug your computer from
the electrical outlet before removing the cover.
6 Remove the computer cover.
• For a mini tower computer, see "Removing the Computer Cover" on
page 22.
• For a desktop computer, see "Removing the Computer Cover" on
page 32.
• For a small form factor computer, see "Removing the Computer
Cover" on page 43.
• For an ultra small form factor computer, see "Removing the Computer
Cover" on page 55.
NOTICE:
Before touching anything inside your computer, ground yourself by
touching an unpainted metal surface, such as the metal at the back of the computer.
While you work, periodically touch an unpainted metal surface to dissipate any
static electricity that could harm internal components.
Quick Reference Guide
15