Dell U2913WM Monitor - Manual (Page 51)

When monitor enters Power Save mode, the following message appears:
Activate the computer and wake up the monitor to gain access to the OSD
If you press any button other than the power button one of the following messages will appear depending on the selected input:
VGA/DVI-D/DP/mDP/HDMI input
When Uniformity Compensation is set to “Calibrated” or “User”, the manual brightness / contrast adjustment is disabled.