Dell OptiPlex 755 User Manual page 126

6 Replace the riser.
7 Replace the computer cover (see "Replacing the Computer Cover" on page 317).
8 Boot your computer and enter system setup (see "Entering System Setup" on page 280). Use the
esata option to enable the eSATA drive.
126
Expansion Cards
1 3
riser-card cage
2 4
slots
riser cards (2)
system board connectors (2)
1
2
3
4