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I've tried searching for answers but haven't come up with anything useful.

I installed Ubuntu about a month ago on my desktop computer. It has worked great initially, but just the other day my main monitor has now stopped being detected completely. I've read about the monitor maybe being deactivated or such, but I can't find it anywhere.

I've tried unplugging it and plugging it in again after restarting and that didn't work. I've tried installing ARandR but it doesn't detect my other monitor.

I dual boot my computer with Windows and it has no problem detecting my monitor as normal, which is really strange. I didn't do anything in particular before I got this problem, like install an update or such, so it's strange that it just suddenly stopped working.

Pleas help! I use Ubuntu for school and I think it works better than Windows for what I'm doing. It sucks that things just stop working for apparently no reason.

Edit: Output from xrandr --listmonitors: xrandr: Failed to get size of gamma for output default Monitors: 1 0: +*default 1920/508x1080/286+0+0 default

Edit: RESOLVED

Gaennil
  • 269

6 Answers6

30

I had a similar issue like this. I downloaded and selected the proprietary drivers I needed in software&updates->additional drivers, and did a couple of restarts. You can check which driver you need with:

ubuntu-drivers devices

Select the right one and restart. It should resolve itself. If that doesn't work try this:

sudo apt-get purge 'nvidia*'
sudo add-apt-repository ppa:graphics-drivers
sudo apt-get update
sudo ubuntu-drivers autoinstall
Mike Rawding
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8

Uninstalling intel drivers was what actually did the trick for me:

sudo apt-get purge xserver-xorg-video-intel
Yuri Ghensev
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0

If nothing else works: probably it is a specific issue that I had here, with my old M6700 laptop, but I could solve this problem by using an old VGA cable instead of HDMI.

The monitor was not identified with the HDMI, but is identified immediately with VGA.

Regarding the advantages of HDMI over VGA - regarding the picture I get - it looks the same... I don't use audio from the screen, so no worries there.

Rani Pinchuk
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0

I run a Thinkpad Extreme Gen 2 on Ubunutu 20.04 (Windows 10 Dual Boot). The notebook is Windows native. I rebooted with Windows and my external monitor was detected, then I have shut the computer down and reboot with Ubuntu, then the monitor was detected.

Note: The exact same pattern came up 1 year ago on Ubuntu 19 with the Intel Network drivers, that's how I got the idea.

Rémy Hosseinkhan Boucher
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0

In my case it helped removing the *-nvidia.rules under /lib/udev/rules.d and rebooting

Martin Hansen
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0

I would suggest you to simply go to software & update, go to additional drivers and then degrade your driver version. Example Using NVIDIA driver metapackage from nvidia-driver-515 TO Using NVIDIA driver metapackage from nvidia-driver-470-SERVER

Ankit Kumar
  • 141
  • 7