Gfilui

After booting to the GUI in 12.04, I attempt to move to the virtual terminal (or shell, or tty) via Ctrl-Alt-F1 (F1 through F6), and the screen remains blank. I have tried all 6 tty instances and the results are the same. Ctrl-alt-F7 brings me back to the GUI without a problem. Any thoughts?

This is usually caused because the graphical text-mode resolution set at boot up is not compatible with your video card. The solution is to switch to true text-mode by configuring Grub appropriately:

1. Open the terminal with Ctrl+Alt+T
   


2. 
   

   Paste the below, and enter your password when asked:

   
   
   

   sudo sed -i -e 's/#GRUB_TERMINAL/GRUB_TERMINAL/g' /etc/default/grub
   

   
   



3. Then type sudo update-grub



4. Reboot and the virtual terminals should now work.

What fixed this for me was adding nomodeset to the GRUB_CMDLINE_LINUX_DEFAULT line in the /etc/default/grub file. Here's how:

1. Type in terminal: gksu gedit /etc/default/grub



2. 
   

   Search for this line: GRUB_CMDLINE_LINUX_DEFAULT

   
   
   

   So for example if you have:

   
   
   

   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"
   

   
   
   

   change it to:

   
   
   

   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1 nomodeset"
   

   
   



3. After you finish, update grub (sudo update-grub) and reboot (sudo reboot) for the changes to take effect.

Optional: You could add nomodeset vga=xxx (not just nomodeset), the xxx is a VESA screen code that best matches your screen resolution. Take a look at this.

This is for newer version of Ubuntu:

1. 
   

   Edit the GRUB configuration file:

   
   
   

   sudo nano /etc/default/grub
   

   
   


2. 
   

   Locate the line

   
   
   

   #GRUB_GFXMODE=640x480
   

   
   
   

   change it to

   
   
   

   GRUB_GFXMODE=auto
   

   
   
   

   and save the file.

   
   


3. 
   

   Then update grub

   
   
   

   sudo update-grub
   

   
   

Please take a look at my question at https://answers.launchpad.net/ubuntu/+question/643882, with regards to virtual terminal not functioning on Ubuntu 16.04 on Lenovo Thinkpad T400.

The solution i presented is geared towards user with Hybrid Graphics Card, in particular, AMD/ATI graphics card and Intel integrated graphics card. For me, disabling the intel graphics card and enabling the opensource ATI/AMD radeon module helps in my case.

If you are using a old Radeon graphics card like mine (Radeon HD 3450/3470), now you can switch between virtual terminal and graphical desktop with ease to troubleshoot potential issues.

If adding blacklist intel_graphics_card in /etc/modprobe.d/blacklist.conf and running

sudo depmod -a 

still doesn't work due to linux kernel or other dependencies, you are advised to add modprobe.blacklist=<module_name> to /etc/default/grub like the following example:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash crashkernel=384M-:128M radeon.dpm=1 modprobe.blacklist=i915"

You need to shut down the graphics driver after you Ctrl+Alt+F1 before you try to install the Nvidia driver

As in sudo /etc/init.d/lightdm stop