Dell Precision WorkStation 420 Service Manual page 38

Figure 22. Installing an Expansion Card
5. When the card is firmly seated in the connector, secure the card's mounting bracket to the chassis with the screw you removed in
the removal procedure.
6. Connect any cables that should be attached to the card.
Expansion-Card Guide and Fan
Figure 23. Expansion-Card Guide and Fan Removal
To remove the expansion-card guide and fan, perform the following steps.
CAUTION: Before you remove the computer cover, see
1. Rotate the power supply away from the system board.
2. Remove the AGP card brace.
3. Remove all full-length expansion
4. Press down on the top of the card guide to release the tab from its slot, located on the lower-left area on the front of the chassis (see
Figure 23).
5. Rotate the top of the card guide away from the chassis front.
6. Disconnect the fan power cable from its connector on the system board.
7. Lift the expansion-card guide and its attached fan out of the chassis.
Figure 24. Expansion-Card Guide Fan Removal
1 Expansion card
2 Expansion-card connector
3 Card edge connector
1 Tab
2 Expansion-card guide
"Precautionary
cards.
Measures."
step 5 of