Dell P3418HW - Contrast; Input Source

Operating the Monitor │ 35
Contrast Allows you to adjust the contrast or the degree of
difference between darkness and lightness on the monitor
screen. Adjust brightness first, and adjust contrast only if
you need further adjustment.
Press the key to increase contrast and press the key
to decrease contrast (min 0 ~ max 100).
Input Source Use the Input Source menu to select between different
video signals that may be connected to your monitor.
DP Select DP input when you are using the DP connector.
Push to select the DP input source.
mDP Select mDP input when you are using the Mini DisplayPort
connector. Push to select the Mini DisplayPort input
source.
HDMI 1 Select HDMI 1 input when you are using the HDMI 1
connector. Push to select the HDMI 1 input source.
HDMI 2 Select HDMI 2 input when you are using the HDMI 2
connector. Push to select the HDMI 2 input source.
Auto Select Select Auto Select to scan for available input signals.
Reset Input
Source
Reset your monitor input settings to the factory settings.