I have been facing this since I changed my monitor from a CRT to LCD.

Ubuntu version: Ubuntu 9.04 kernel 2.6.28-11-generic

This is quite old machine, I am trying to access it after years - then I understood my monitor was not working - so I replaced it and then this issue started occurring.

There are two OS installed - Windows and Ubuntu. This error:

"Can not display this video mode optimum resolution 1024x768 60Hz"

occurs only for Ubuntu. Windows works perfectly fine.

I followed the following thread to resolve this issue :"Can not display this video mode" error during boot, followed by empty desktop

I faced some other difficulties while doing that as well:

1. When I run gksu gedit /etc/default/grub, I get this error:

   gksu Gtk-WARNING **: cannot open display: :0

   I solved this by using vi (I also had to use sudo -H)

   sudo -H vi /etc/default/grub

   I observed that this was a new blank file and so I added

   GRUB_GFXMODE=640x480

   to it.

2. After saving the file, when I tried to run sudo update-grub2 It said update-grub2 command not found. So I ran sudo update-grub and it worked fine.

I have tried these resolutions:

• 640x480
• 1024x768
• 1280x800

None worked and I am still getting the same error.

4 Sorted by: Reset to default

Know someone who can answer? Share a link to this question via email, Twitter, or Facebook.

Your Answer

Sign up or log in

Sign up using Google Sign up using Facebook Sign up using Email and Password Submit

Post as a guest

Post Your Answer Discard

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy