Dell OptiPlex 3090 Small Form Factor Service Manual page 64

Steps
1. Align and lower the system board into the system until the connectors at the back of the system board align with the slots
on the chassis, and the screw holes on the system board align with the standoffs on the system.
2. Replace the seven (6-32) screws and the single standoff (M2X4) screw to secure the system board to the chassis.
3. Align and lower the I/O panel into the slot on the chassis.
4. Replace the single (6-32) screws to secure the I/O panel to the chassis.
5. Reconnect the intrusion switch cable.
6. Reconnect the system board power supply cables.
7. Reconnect the power button switch cable.
8. Reconnect the system fan cable.
9. Reconnect the processor power supply cable.
10. Reconnect the SATA cables.
11. Reconnect the SATA power cable.
12. Reconnect the internal speaker cables.
Next steps
1. Install the processor.
2. Install the heats-sink and fan assembly.
64 Removing and installing components