Dell Precision T3400 (Late 2007) - Manual (Page 169)

Adding and Replacing Parts
169
If you removed a network adapter card, enter System Setup (see "Entering
System Setup" on page 81), select Integrated NIC, and then change the
setting to On.
NOTE:
Connect your external audio devices or your network cable to the
audio and network connectors on the back panel of the computer.
Installing a PCI Card
CAUTION:
Before you begin any of the procedures in this section, follow the
safety instructions in the Product Information Guide.
NOTE:
Dell offers a customer kit for Audigy II and IEEE 1394 PCI cards that includes
a front-mounted IEEE 1394 connector. For more information about connecting the
card cable to the I/O panel, see "I/O Panel" on page 251.
1 Follow the procedures in "Before You Begin" on page 143.
2 Remove the computer cover (see "Removing the Computer Cover" on
page 145).
3 Press the release tabs on the card retention door and pivot the door open.
1 release tab 2 card retention door
2
1