Dell OptiPlex 390 (Mid 2011) - Manual (Page 42)

Installing the Chassis Fan
1. Place the chassis fan in the chassis.
2. Pass the four grommets through the chassis and slide outward along the
grooves to secure them in place.
3. Connect the fan cable to the system board.
4. Install the
cover .
5. Follow the procedures in After Working Inside Your Computer .
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