Dell Precision T5400 (Late 2007) - Manual (Page 204)

204 Adding and Replacing Parts
8 Rotate the card retention door until it snaps into place.
NOTICE: Do not route card cables over or behind the cards. Cables routed over the
cards can prevent the computer cover from closing properly or cause damage to
the equipment.
9 Connect any cables that should be attached to the card.
See the documentation for the card for information about the card’s cable
connections.
10 Ensure that all connectors are properly cabled and firmly seated.
1 card retention door 2 release tab
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