I'm using Ubuntu 13.04 and my graphics card is Nvidia GF 620M. For some reason, Ubuntu is using the Ivy Bridge processor. It works fine, though.

The only issue I'm facing is the brightness. I can't change it. I'm trying to change it through the hot keys in my Acer, but it is not changing. Anyway to do that?

  • Please provide us with your PC model.
    – edwin
    Jul 12, 2013 at 21:00
  • Acer aspire v5-571
    – Antoine
    Jul 12, 2013 at 21:45

1 Answer 1


I have found a cure for this which has worked for me

  • Ubuntu 13.04
  • Packard Bell
    • Intel® Core™ i3-2350M CPU @ 2.30GHz × 4
    • Intel® Sandybridge Mobile
    • 64-bit


The F11 and F12 control the brightness, but although the tooltips showed that the brightness was changing, the screen didn't change.

enter image description hereenter image description hereenter image description hereenter image description here


I cured this by opening and editing the grub menu.

  1. Open Terminal with Ctrl + Alt + T
  2. I typed in sudo gedit /etc/default/grub, entered my password
  3. I changed the line which read GRUB_CMDLINE_LINUX="" to GRUB_CMDLINE_LINUX="acpi_backlight=vendor"
  4. Saved and Closed gedit.
  5. in Terminal I updated the Grub with sudo update-grub
  6. I re-booted the laptop

Everything is now working.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .