Dell OptiPlex 9020 All In One (Mid 2013) - Manual (Page 28)

Installing the I/O Board Shield
1. Connect the power-connector cable to the system board.
2. Place the I/O board shield on the computer.
3. Pass the power connector and fix it to the socket. Tighten the screws that secure the I/O board shield to the
chassis.
4. Tighten the screws that secure the power connector to the I/O shield.
5. Place the I/O panel on the computer.
6. Install:
a) power-supply fan
b) system-board shield
c) VESA mount bracket
d) back cover
e) VESA stand
7. Follow the procedures in After Working Inside Your Computer .
Removing the Power Supply Unit (PSU)
1. Follow the procedures in Before Working Inside Your Computer .
2. Remove the:
a) VESA stand
b) back cover
c) VESA mount bracket
d) system-board shield
e) input/output (I/O) board shield
f) power-supply fan
3. Disconnect the power-supply cables from the system board. Unthread the cable from the hooks in the computer.
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