My Ubuntu system isn't recognising my HDMI connected monitor. Help!

I have been trying to have a dual monitor setup on a Linux computer and I have been in a fix. The system is running Ubuntu 22.04 LTS on a Dell XPS 13. And I have been trying to setup an external monitor using HDMI. The monitor is an LG 27GL850-B connected through HDMI.

The challenge is that the monitor is not detected at all by Linux. The monitor works fine with the same setup on other devices. I have done restarting and all those cliche troubleshooting moves.

What can I do on the Ubuntu side for the monitor to even be detected by the graphics card?

By cliche troubleshooting I’m assuming you mean the display settings within the distro? Have you also restarted the service; sudo systemctl restart display-manager

It is laughable that the poster above me recommended a cliche software solution to a purely hardware solution. I think the solution to this should be purely on hardware and system settings.

If there is a confirmation that there is no problem with physical connections, one might need to BIOS to check settings.

Enter the BIOS after reboot by pressing F2 repeatedly. Go to display or graphics settings option in BIOS. If the internal monitor was set as the only display, look for an option that supports Multi Monitor and check it. If your computer has a dedicated graphics card, you should check it to support external displays.

If it is NVIDIA, you would see, Enable Optimus Technology. Activate it and save. That should solve the problem.

Can I laugh at you if this doesn’t resolve his issue?

The problem is that I am facing the same issue with Ubuntu. As HDMI works perfectly for Windows but if you are going to make a presentation with Ubuntu system it is not recognized and still not working.

Hi, I faced the same issue today. HDMI output crashed so my external monitor was not recognized.

I solved the issue by re-installing the NVidia driver to a lower version. My machine was installing nvidia-driver-545 by default, but the installation failed each time.
I installed the version 535, and got my external monitor working.

Step 1: Clean Up Previous NVIDIA Installations

Ensure a clean environment by removing existing NVIDIA drivers and DKMS files:

sudo apt-get purge ‘^nvidia-.*’ sudo apt-get autoremove sudo apt-get autoclean sudo rm /var/crash/nvidia-dkms-545.0.crash

Step 2: Reinstall Necessary Dependencies

sudo apt-get install build-essential dkms linux-headers-$(uname -r) sudo apt-get install libc6-dev libglvnd-dev pkg-config

Step 3: Add the Graphics Drivers PPA and Update

sudo add-apt-repository ppa:graphics-drivers/ppa sudo apt-get update

Step 4: Install the NVIDIA Driver

Install the NVIDIA driver using the package manager:

sudo apt-get install nvidia-driver-535

Step 5: Update Initramfs and Reboot

Update initramfs and reboot your system to apply the changes:

sudo update-initramfs -u sudo reboot

Step 6: Verify Secure Boot Status

Ensure that Secure Boot is disabled in your BIOS/UEFI settings, as it can prevent third-party drivers from loading. Reboot your system, enter the BIOS/UEFI setup, and disable Secure Boot if it is enabled.


It is helped for me, thank you very much :fire: :fire: :fire: :fire:

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