Dell OptiPlex XE3 Small Form Factor Service Manual page 51

f Heat sink fan
3 To release the PSU:
a Disconnect the CPU power cable from the system board [1].
b Unroute the power cables from the retention clips on the chassis [2,3].
c Disconnect the system power cable from the connector on the system board [4].
4 To remove the PSU:
a Remove the screws (3) that secure the PSU to the system [1].
b Press the blue release tab at the rear end of the PSU unit [2].
c Slide the PSU and lift it away from the system [3].
Disassembly and reassembly 51