Dell OptiPlex 990 (Early 2011) - Manual (Page 43)

Installing The Power Supply
1. Place the power supply in the chassis and slide outward to secure it.
2. Tighten the three screws securing the power supply to the back of the
computer.
3. Connect the power cable to the system board.
4. Thread the power cable into the chassis clips.
5. Connect the power cable to the system board.
6. Install the
fan shelter .
7. Install the drive cage .
8. Install the front bezel .
9. Install the cover .
10. Follow the procedures in After Working Inside Your Computer .
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