Dell OptiPlex GX260 Series System User's Manual page 116

NOTICE: To disconnect a network cable, first unplug the cable from your computer, and then unplug it from the
network wall jack.
2. Turn off any attached devices and disconnect them from their electrical outlets.
3. Disconnect the computer power cable from the wall outlet, and then press the power button to ground the system
board.
4. Remove the computer
5. Open the computer cover.
6. Remove the card cage.
a. Check any cables connected to cards through the back-panel openings. Disconnect any cables that will not reach
the card cage once the cage is removed from the computer.
b. Gently pull the handle and lift the card cage up and away from the computer.
Removing the Card Cage
1 card cage
2 handle
7. Press the lever on the retention arm and raise the retention arm.
Raising the Retention Arm and Installing a Serial Port Adapter
stand, if it is attached.