Dell U4021QW User Manual page 63

If either Thunderbolt™ (90 W), DP, HDMI input is selected and the corresponding
cable is not connected, a floating dialog box as shown below appears.
See Troubleshooting
No DP Cable
The display will go into Standby Mode in 4 minutes.
www.dell.com/U4021QW
No HDMI 1 Cable
The display will go into Standby Mode in 4 minutes.
www.dell.com/U4021QW
No HDMI 2 Cable
The display will go into Standby Mode in 4 minutes.
www.dell.com/U4021QW
No Thunderbolt (90W) Cable
The display will go into Standby Mode in 4 minutes.
www.dell.com/U4021QW
for more information.
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Operating the monitor | 63