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I'm new to linux systems in general (I'm using Ubuntu 16.04 LTS) and I'm having difficulty in changing the brightness of my notebook.

When I use the Fn+F8 or Fn+F9 the brightness bar shows up but there is no change in the actual brightness of the screen.

I tried every method discribed in this post (How to adjust screen brightness in Ubuntu 14.04 (Trusty Tahr)?) to no success. Installing and using the xbacklight has no effect, same for editing the brightness file in the "intel_backlight" file.

Anyone knows how to solve this?

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  • 1
    I had the same problem using Toshiba C660 satelite a few years back. It wouldn't work, until I used the nvidia driver from the "additional drivers" tab, couldn't get it to fix, using the open-source driver. Does it happen to you, which driver are you using? – Mookey Apr 26 '16 at 6:30
  • I think you should add at least the model name – lrkwz Apr 26 '16 at 6:36
  • 1
    The graphics card is an Intel® HD Graphics 3000. I'm still not very familiar with the way linux handles the computer drivers and all, so I'm not sure what do you mean about "additional drivers tab". – Andrei Apr 26 '16 at 17:33
  • I found a strange workaround on my laptop (compaq cq70). Instead of pressing Fn+f7 to dim and Fn+f8 to brighten, I am able to use Ctrl+f10 to dim and press Ctrl+f11 to brighten. – Joel Sjögren Jul 24 '16 at 11:32
59

This does not make your brightness function keys work, but is a workround.

Install Brightness Controller with the following commands:

sudo add-apt-repository ppa:apandada1/brightness-controller
sudo apt update

For Version 1 with up to 4 Monitor Support:

sudo apt install brightness-controller-simple

]([![Brightness Controller Version 1

For Version 2 with Multi Monitor Support and other features:

sudo apt install brightness-controller

enter image description here Note: This does not decrease the intensity of backlight, so won't save your batteries. But you can use this as a last resort to save your eyes. This also works in desktops, where there is no option to control brightness.

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30

Hardware brightness buttons 🔅 🔆

Since Ubuntu LTS 18.04

Here is every step required for xbacklight control:

  1. $ sudo nano /etc/default/grub and replace the corresponding line with GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
  2. $ sudo update-grub
  3. No joking, make sure that the appropriate drivers are actually installed: $ sudo apt install xbacklight xorg xserver-xorg-video-intel
  4. Issuing $ find /sys -type f -name brightness should yield something like /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/brightness
  5. $ cd /sys/class This directory should contain a soft link called brightness to the brightness device discovered in the previous step. Should it be missing, create it: $ sudo ln -s /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/brightness /sys/class/brightness
  6. $ sudo nano /etc/X11/xorg.conf should read:
Section "Device"
    Identifier      "Device0"
    Driver          "intel"
    Option          "Backlight"      "intel_backlight"
EndSection

Section "Monitor"
    Identifier      "Monitor0"
EndSection

Section "Screen"
    Identifier      "Screen0"
    Monitor         "Monitor0"
    Device          "Device0"
EndSection
  1. The assignment of the physical XF86MonBrightnessDown and XF86MonBrightnessUp keys is explained here for Xubuntu LTS or XFCE users.
  2. Finally, reboot for these changes to take effect.

Finer-grained brightness control (all Ubuntu versions)

If brightness control happens to be too coarse, then make this additional adjustment.

Ubuntu LTS 16.04

To find out if you have integrated Intel video graphics, enter the following command:

$ ls /sys/class/backlight/
    intel_backlight  panasonic

At least intel_backlight should be mentioned, most probably in addition to an OEM name like for example panasonic, dell_backlight, etc.

If this is the case, proceed with creating the following file

$ sudo nano /usr/share/X11/xorg.conf.d/20-intel.conf

containing the following lines:

Section "Device"
        Identifier  "card0"
        Driver      "intel"
        Option      "Backlight"  "intel_backlight"
        BusID       "PCI:0:2:0"
EndSection

Reboot, and enjoy your backlight buttons! [Source]

Before Ubuntu LTS 16.04

Under (X)Ubuntu 14.04 LTS, brightness control on my Panasonic Toughbook CF-52 used to work fine by adding acpi_osi=Linux to the GRUB_CMDLINE_LINUX_DEFAULT= line in /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux"

and issuing

$ sudo update-grub

after editing and before rebooting.

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  • 2
    I tried this fix on my laptop which has an integrated Intel gfx card (with a backlight as revealed by the ls command as suggested), and with 2nd Nvidia 960M as well. On reboot I get a purple screen, but nothing else being displayed - I can change the background brightness, but I can't log in, as I can't see anything on the screen except a full screen purple wash. – Tony Suffolk 66 Jan 27 '17 at 11:31
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    Solved my issue with Lenovo W520 @ Ubuntu 16.04. – Igor Pomaranskiy Mar 25 '17 at 11:10
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    This answers even works for me!!!. I am Linux mit xfce user.thanks alot Gin Gordon – noone Jul 22 '17 at 8:48
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    Fixed issue on 17.04 Ubuntu as well, fn keys now work again to control brightness. – Michael Jackson Sep 27 '17 at 13:36
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    The post-16.04 version also works on Debian Stretch – Jonathan Landrum Jan 22 '18 at 3:20
6

Another option is the application Redshift, which in addition to adjusting brightness can also adjust the color temperature to reduce the blue light at night.

Example usage: redshift -b 0.8 will set the brightness to 0.8 on a scale of 0 to 1

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  • When using redshift, I get the problem of multiple commands being stacked, causing the screen to flicker. If i close my terminal, redshift stops working – fastenedrex Apr 14 '17 at 16:21
4

I use Lenovo Z570 and adding acpi_backlight=none to /etc/default/grub and updating grub worked nicely with Fn key.

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1

In 16.04 there is a package in the repos called "backlight-indicator" which will use your camera to set backlight (or not) and differentially set it for AC and/or battery usage.

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0

I fixed this on my Asus UX303UB with a little difference:

  • set to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=" (acpi_osi= did it for me, other options didn't work, got this from here). Of course after this run update-grub. This make function keys respond showing the Ubuntu notification, but doesn't really change brightness. One more thing taken from other answers:
  • sudo nano /usr/share/X11/xorg.conf.d/20-intel.conf

with contents:

Section "Device"
    Identifier  "card0"
    Driver      "intel"
    Option      "Backlight"  "intel_backlight"
    BusID       "PCI:0:2:0"
EndSection

Now the only problem is to associate Fn+F7 to xset dpms force standby to turn off the screen.

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0

In my case, the problem was because of some issue with my graphics drivers. Changing them to a stable version solved the issue.

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0

In XFCE, you must enable "Handle display brightness keys" on XFCE Power Manager, under the General tab.

enter image description here

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