Dell UltraSharp U3821DW User Manual page 78

No Input Signal
when user controls
are pressed
The picture does
not fill the entire
screen
No video at HDMI/
DisplayPort/USB
Type-C port
No network
connection
│
78 Troubleshooting
No picture, the LED
light is white
The picture cannot
fill the height or
width of the screen
When connected to
some dongle/
docking device at
the port, there is no
video when
unplugging/plugging
the cable from the
notebook
Network dropped or
intermittent
• Check the signal source. Ensure the
computer is not in the power saving
mode by moving the mouse or
pressing any key on the keyboard.
• Check whether the signal cable is
plugged in properly. Re-plug the
signal cable if necessary.
• Reset the computer or video player.
• Due to different video formats
(aspect ratio) of DVDs, the monitor
may display in full screen.
• Run the built-in diagnostics.
• Unplug the HDMI/DisplayPort/USB
Type-C cable from dongle/docking
device, then plug the docking HDMI/
DisplayPort/USB Type-C cable to the
notebook.
• Check to ensure USB-C
Prioritization is set to High Data
Speed.
• Do not turn Off the display during
network connection.