Dell OptiPlex 3070 Small Form Factor Service Manual page 60

a) Remove the screw that secures the I/O panel [1].
b) Rotate the I/O panel and remove it from the system [2].
c) Disconnect the hard drive data cable [3], optical drive data cable [4] and power cable [5] from the connectors on the system
board.
5. Disconnect the following cables from the connectors on the system board:
a) Intrusion switch [1]
b) CPU power [2]
c) Power switch [3]
6. Unroute the PSU cables from the retention clips [4].
60 Removing and installing components