Dell OptiPlex 360 (Late 2008) - Manual (Page 110)

110 Power Supply
Desktop Computer Power Supply
Removing the Power Supply From the Desktop Computer
1 Follow the procedure in "Before Working on Your Computer" on page 9.
2 Remove the computer cover (see "Removing the Desktop Computer
Cover" on page 21).
3 Disconnect the power cables from the system board and the drives.
CAUTION: Note the routing of the power cables underneath the tabs in the
computer chassis as you remove them from the system board and drives. You must
route these cables properly when you replace them to prevent them from being
pinched or crimped.
4 Remove the two screws that attach the power supply to the back of the
computer chassis.
5 Remove the optical drive and set it aside (see "Removing the Optical Drive
From the Desktop Computer" on page 59).