Dell OptiPlex 5270 All-in-One Service Manual page 78

c) Slide the power button board cable under the antenna cable [1].
d) Slide the power button board cable under the antenna cable, then adhere the power button board cable to the display assembly
base [2].
e) Slide the power button board cable into the socket on the system board and close the latch to secure the cable [3].
78 Removing and Installing components