Score:0

No graphical output if computer boots with monitor set to different input

gb flag
jl6

My Dell 3008WFP monitor supports multiple inputs. I have two computers, an Ubuntu 22.04 machine connected to the DisplayPort input, and a Windows Surface Pro machine connected to the HDMI input.

When my Ubuntu 22.04 PC boots up with the input selection set to HDMI, and I then switch the input to DisplayPort, there is no graphical output. The same happens if I boot the PC with the monitor switched off, and then turn it on. Not only is there no graphical output, the monitor goes into power saving mode as if there isn't any signal of any kind being received from the PC.

I am able to recover by pressing Ctrl+Shift+F1 to get to a console, then restarting lightdm with sudo systemctl restart lightdm.

If I boot the Ubuntu 22.04 PC with the input selection set to DisplayPort, everything works fine.

It seems like the monitor is not detected if it isn't available, and on the right input, at boot time.

This is a longstanding issue that occurs rarely enough that I was happy to wait and see if the upgrade from 20.04 to 22.04 fixed it. It did not.

Other possibly relevant information: the graphics card in the PC is a AMD Radeon RX 5700.

ChanganAuto avatar
us flag
*It seems like the monitor is not detected if it isn't available, and on the right input, at boot time.* Exactly, that's what should be expected so, not an issue, therefore no "fix" is expected.
jl6 avatar
gb flag
jl6
My expectation is that when a monitor is plugged into a running system, the system detects it and uses it.
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