Dell UltraSharp 27 User Manual page 80

If either DP, HDMI or Thunderbolt (90W) input is selected and the corresponding cable
is not connected, a floating dialog box as shown below appears.
See Troubleshooting
80 | Operating the monitor
No DP Cable
The display will go into Standby Mode in 4 minutes.
www.dell.com/U2724DE
No HDMI Cable
The display will go into Standby Mode in 4 minutes.
www.dell.com/U2724DE
No Thunderbolt(90W) Cable
The display will go into Standby Mode in 4 minutes.
www.dell.com/U2724DE
for more information.
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