Dell Precision T7400 (Late 2007) - Manual (Page 274)

274 Adding and Replacing Parts
8 Disconnect the speaker cable from the system board.
9 Disconnect the front fan and the card fan from the system board.
10 Unscrew the two screws that hold the processor and card fan case in place
and lift it away from the computer. These screws help to secure the system
board in place.
1 memory fan (only present on
computers without memory riser
cards)
2 fan support structure
2
1