Dell OptiPlex 9020 (Mid 2013) - Manual (Page 21)

5. Slide the power supply inward and lift the power supply unit out of the computer.
Installing The Power Supply Unit
1. Place the power supply in the chassis and slide outward to secure it.
2. Tighten the screws to secure the power supply to the back of the computer.
3. Tighten the screws that secure the power supply to the chassis.
4. Connect the power cables to the system board.
5. Install:
a) intrusion switch
b) drive cage
c) front bezel
d) cover
6. Follow the procedures in After Working Inside Your Computer .
Removing the Heat Sink Assembly
1. Follow the procedures in Before Working Inside Your Computer .
2. Remove:
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