Dell S2817Q User Manual page 41

Activate the computer and wake up the monitor to gain access to the OSD.
If you press any button other than the power button, the following messages will appear
depending on the selected input:
If either DP, mDP, HDMI/MHL input is selected and the corresponding cable is not
connected, a floating dialog box as shown below appears.
or
or
See Troubleshooting for more information.
Operating the Monitor | 41