Dell Precision 390 - Manual (Page 75)

1. Follow the procedures in Before You Begin .
2. Remove the computer cover (see Removing the Computer Cover ).
3. Place the fan flush with the side of the power supply and engage the fan hooks in the three fan slots in the side of the power supply.
4. Slide the fan down until it clicks into place.
5. Connect the fan cable to the fan connector on the system board.
To remove the fan:
1. Disconnect the fan cable from the fan and from the fan connector on the system board.
2. Press in on the fan release tab and lift to remove the fan.
3. Replace the computer cover. See Replacing the Computer Cover .
Drive-Panel Inserts
NOTICE: When placing the fan in the computer, ensure that the cables of other components, such as the power supply, remain in their proper position.
1 fan slots (3) 2 fan release tab 3 fan cable
4 fan connector on system board 5 power supply
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before removing the cover.