After an NVIDIA GeForce GTX 470 official driver installation I can't see the login screen.
I only see a blinking "_" in the top, left corner of a black screen. But I can't type anything.
I also can't run grub (holding shift while boot).

After holding the power button I can see some output from the terminal.

How can I handle this issue - reinstall/restore the driver or reinstall system?

  • Note that the flashing cursor is because you are in tty7. To switch between tty's, use Alt-F1 to Alt-F6. That should give you a login prompt. To go back to tty7, use Alt-F7. Once at a prompt and logged in, you can check out logs to try to find out what the problem might be. Aug 2 '13 at 0:52

I had a similar issue on my Macbook, this was because the Nvidia drivers does not work in UEFI mode. I had to convert the installation to legacy mode:


Since you do not mention anything other about your hardware and installation, it is hard to make any assumptions. If you don't know right off that you installed Ubuntu in UEFI mode, here is how you check it:

[ -d /sys/firmware/efi ] && echo "Installed in EFI mode" || echo "Installed in Legacy mode"

Further instructions here:


  • The problem is that I can't execute any commands. I can't see anything I write. There is always this "_" character.
    – czerasz
    Aug 1 '13 at 17:35
  • Can you boot with recovery mode? That actually just uses nomodeset as a default.
    – oldfred
    Aug 1 '13 at 18:11

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