Dell UltraSharp U2421HE User Manual page 58

Problem
The picture does
not fill the entire
screen
No image
when using
USB Type-C
connection
to computer,
laptop, and so on
No charging
when using
USB Type-C
connection
to computer,
laptop, and so on
Intermittent
charging
when using
USB Type-C
connection to
computer,
laptop, and so on
No image
when using DP
connection to
the PC
No image when
using USB
Type-C MST
No network
connection
58 | Troubleshooting
What you Possible solutions
experience
The picture • Due to different video formats (aspect ratio) of
cannot fill the
height or width • Run the built-in diagnostics.
of the screen
Black screen • Verify if the USB Type-C interface of the device can
• Verify if the device required more than 65 W power
• USB Type-C interface of device cannot support DP
• Set Windows to Projection mode.
• Ensure that the USB Type-C cable is not damaged.
No charging • Verify if the device can support one of 5 V/9 V/15
• Verify if the Notebook requires a >65 W power
• If the Notebook requires a >65 W power adaptor, it
• Ensure that you use only Dell approved adapter or
• Ensure that the USB Type-C cable is not damaged.
Intermittent • Check if the maximum power consumption of
charging
• Ensure that you use only Dell approved adapter or
• Ensure that the USB Type-C cable is not damaged.
Black screen • Verify which DP standard (DP 1.1a or DP 1.4) is your
• Some DP 1.1a graphics card cannot support
Black screen or • USB Type-C input, Go to OSD menu, under Display
2nd DUT is not
Prime mode
Network • check to ensure data priority is selected in OSD. Do
dropped or
Intermittent
DVDs, the monitor may display in full screen.
support DP alternate mode.
charging.
alternate mode.
V/20 V charging profiles.
adaptor.
may not charge with the USB Type-C connection.
the adapter that comes with the product.
device is over 65 W.
the adapter that comes with the product.
Graphics Card certified to. Download and install the
latest graphics card driver.
DP 1.4 monitors. Go to OSD menu, under Input
Source selection, press and hold DP select
key for 8 sec to change the monitor setting from
DP 1.4 to DP 1.1a.
Info check the Link Rate is HBR2 or HBR3, if Link
Rate is HBR2, suggest to use USB Type-C to DP
cable to turn on MST.
not toggle Off/On the power button when network
is connected, keeps the power button On.