Score:0

HDMI not detected anymore

br flag

I had a normally working Lenovo S27i-10 monitor on the HMDI port of my Ubuntu Mate 20.04 system. It is suddenly not detected anymore:

henk@henk-N24-25BU ~> xrandr | grep 'connected'                                                  
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)  

Monitor works normally on VGA. The monitor shows as disconnected on a different laptop running Xubuntu as well. Monitor works perfectly well on Windows laptop using the same HDMI cable.

How can I connect this monitor on the HMDI port again on Ubuntu? (in other words, how can I diagnose where the problem is and solve it).

David avatar
cn flag
If 2 different machines tell you they can not connect then its the monitor and or the cable that is bad.
user39444 avatar
br flag
@David I have tried different HDMI cables. I don't understand why the monitor worked in the morning with a cable with which it didn't work anymore in the afternoon.
user39444 avatar
br flag
@Community - I would like to get help with diagnosing this problem. What do you need to know what is happening here. End goal was stated in the question - how can I get the HDMI status to "connected" again.
David avatar
cn flag
Things break. Something has happened to the HDMI connection in the monitor it seems.
user39444 avatar
br flag
OK, the monitor is actually brand new. How do I know it is the monitor?
user39444 avatar
br flag
@David - I have checked the monitor on a Windows laptop using the same HDMI cable and it works perfectly.
David avatar
cn flag
Hove you been able to test the HDMI on the computer where it no longer works with another monitor?
Score:0
br flag

Solved by:

sudo dpkg-reconfigure gdm3

This produced:

gdm.service is not active, cannot reload.
invoke-rc.d: initscript gdm3, action "reload" failed.

after which everything worked again.

Score:0
br flag

I've got Lenovo P50s laptop with Kubuntu 20.04 and it too stopped detecting my HDMI monitor recently.

The solution as suggested by @BeastOfCaerbannog didn't work for me.

After today's slew of package updates though, it started working again, so perhaps it looks like a software defect, that was subsequently fixed again.

br flag
Now on Kubuntu 21.04, HDMI monitor worked until today's updates. Now it is no longer detected - again.
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