Are the correct drivers installed?
First of all, check that you actually have the correct nvidia drivers installed (this will check whether they are installed and install them if they aren't already):
Fire up a terminal, and then:
- If you want the stable (tested, but old) drivers, do:
sudo apt-get install nvidia-current
- If you want the latest (possibly untested, but fresh from nVidia) drivers, do:
sudo apt-get install nvidia-current-updates
Once you're done with that, restart your computer to check that the drivers are working correctly (check the bottom of the post if they aren't).
Now, shut down your computer (or just shut down the X server(s)), and then remove the VGA cable. Then, plug in the HDMI cable.
Now start up your computer. Is it working?
If not, check that the monitors you have work with another HDMI output (ie: X360, PS3, DVD Player, etc.). If they don't, it might just be your monitors.
If the monitors work but the card isn't working, it may be a defect with the card, or an alternate setup may be required.
If the (newly installed) drivers weren't working:
Hit Ctrl + Alt + F1
You will be shown a terminal. Log in using your username and password.
Stop whatever display manager you're using:
LightDM (Default): sudo service lightdm stop
GDM (GNOME): sudo service gdm stop
KDM (KDE Plasma Workspaces): sudo service kdm stop
Any other display manager (custom/other desktop environments): sudo service [display manager name] stop
Then, uninstall the nvidia drivers:
sudo apt-get remove nvidia-current nvidia-current-updates
Once this is finished, reinstall the nvidia drivers as shown at the top of the post.
Restart the computer:
sudo reboot now
Did it work out in the end?
If all of the above doesn't solve the problem, tell us what didn't work.
If it did work, mark the solution, and upvote it.
I had exactly the same problem with a Laptop HP Pavillion and a GEFORCE GTX 960M. I had problems with the HDMI with both a TV and a beamer.
I finally solved it by installing the latest version of the open source drivers (nvidia-390 at the time of this post).
These steps should do the job: first clean up any eventual mess that there might be by doing
apt-get purge nvidia*
and then you can do the actual installation
add-apt-repository ppa:graphics-drivers/pp
apt update
apt-get install nvidia-387
After rebooting in principle you should obtain a non empty output to
lsmod | grep nvidia
but in my case it was empty and that was why it wasn't working. At the boot Linux wasn't loading the relevant modules. This was UEFI secure boot's fault. Apparently the secure boot didn't like the open source drivers and blocked them from being loaded. This can be fixed by going to the BIOS and disabling it (see here for a more thorough explanation https://askubuntu.com/a/762255).
If it still doesn't work you can try to look for these two possible issues:
- Some other drivers are not blacklisted, e.g. nouveau (https://askubuntu.com/a/951892)
- The file
/etc/X11/xorg.conf isn't there. If so generate it with nvidia-xconfig
Best Answer
For some reason NVidia proprietary drivers seem to work badly on Linux. I had a similar issue with my laptop (HP Pavillion with a GeForce GTX 960M). In the end I solved it by installing a non-proprietary driver.
These steps should do the job: first clean up any eventual mess that there might be by doing
and then you can do the actual installation
After rebooting in principle you should obtain a non empty output to
but in my case it was empty and that was why it wasn't working. At the boot Linux wasn't loading the relevant modules. This was UEFI secure boot's fault. Apparently the secure boot didn't like the open source drivers and blocked them from being loaded. This can be fixed by going to the BIOS and disabling it (see here for a more thorough explanation https://askubuntu.com/a/762255).
If it still doesn't work you can try to look for these two possible issues:
Some other drivers are not blacklisted, e.g. nouveau (https://askubuntu.com/a/951892). The file /etc/X11/xorg.conf isn't there. If so generate it with
nvidia-xconfig