Dell OptiPlex 5270 All-in-One Service Manual page 67

2. To install the PSU cable:
a) Route back the power supply cables through the retention clips in the chassis [1].
b) Slide and replace the power supply socket on the chassis [2].
c) Replace the single (M3x5) screw securing the power supply socket to the I/O bracket [3].
Removing and Installing components 67