Dell Precision 650 - Manual (Page 7)

6. Before you lower the retention arm, ensure that:
l The tops of all cards and filler brackets are flush with the alignment bar.
l The notch in the top of the card or filler bracket fits around the alignment guide.
Press the arm into place, securing the card(s) in the computer.
7. If you are replacing an AGP card, align the AGP card guide with the base and press down on the indentation until the guide stops at the top of the AGP
card.
1 fully seated card
2 not fully seated card
3 bracket within slot
4 bracket caught outside of
slot
1 filler bracket
2 alignment bar
3 alignment guide
4 retention arm