Dell P1913 - Page 46

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 input
If either VGA or DVI-D or DP input is selected and the corresponding cable is not connected, a floating dialog box as shown below appears.
or or
See Solving Problems
for more information.