Dell OptiPlex GX280 - Manual (Page 131)

Replacing the System Board: Small Form-Factor, Small Desktop, and
Small Mini-Tower Computers
1. If your original system board uses a mounting plate rather than a tray to attach to the chassis, replace the existing
system board with the replacement system board:
a. Slide the system board assembly toward the back of the computer, attaching it to the hooks on the floor of the
chassis.
b. Replace the retention screw at the front of the computer.
1 retention screw
2 hooks (4)
2. If your original system board uses a metal tray rather than a mounting plate to attach to the chassis:
a. Detach the system board from the metal tray:
Remove the screw that secures the original board to the metal tray.
Remove the four mounting screws from the heat-sink retention base, and then remove the system board
by sliding the board back and detaching it from the hooks on the metal tray.