Dell OptiPlex Gxi - Manual (Page 87)

System Board Removal: OptiPlex GXi
1. Disconnect all cables from their connectors at the back of the computer.
2. Remove the expansion-card cage.
3. Unlatch and rotate the power supply to the right.
4. Disconnect all cables from the system board.
5. Remove the screw that secures the system board to the bottom of the chassis.
6. Slide the system board toward the front of the chassis until it stops.
7. Carefully lift the system board out of the chassis (be sure to lift evenly and not twist the system board).
If you are replacing a system board, remove the DIMMs, cache memory card, NIC daughter board, and microprocessor from the old system board and install them
on the replacement board.
When you reinstall the system board, before you slide the system board back to lock it in position, push down near each slot to engage the grounding clip onto its
corresponding tab. Push evenly on both sides of the system board as you slide it into position (do not twist the system board).