Dell GX280DT - GX280 Desktop Computer User Manual page 154

Removing the System Board: Desktop and Mini-Tower Computers
1. Shut down the computer through the Start menu.
2. Ensure that your computer and attached devices are turned off. If your computer and attached devices did not automatically turn off when you shut
down your computer, turn them off now.
NOTICE: To disconnect a network cable, first unplug the cable from your computer and then unplug it from the network wall jack.
3. Disconnect any telephone or telecommunication lines from the computer.
4. Disconnect your computer and all attached devices from their electrical outlets, and then press the power button to ground the system board.
CAUTION: To guard against the electrical shock, always unplug your computer from the electrical outlet before opening the cover.
5. Open the computer cover.
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.
6. Remove any components that restrict access to the system board (CD/DVD drive(s), floppy drive, hard drive, I/O panel).
7. Remove the heat sink assembly and processor.
8. Disconnect all cables from the system board.
9. Remove the 10 screws from the system board (see illustrations below for screw locations).
10. Slide the system board assembly toward the front of the computer, and then lift the board up and away.
1 desktop system board
2 screws (10)