Fix Brightness Control Not Working for Ubuntu 14.04 & Linux Mint 17

Care to Share?

Two of the most prominent issue with Ubuntu 13.10 are brightness control and sound. We saw how to fix no sound issue in an older post. In this quick post, we’ll see how to fix brightness function key not working in Ubuntu 14.04.

This article was originally written for Ubuntu 13.10 but it is equally able to fix brightness issue in Ubuntu 14.04 as well as Linux Mint 17.

On my Dell Inspiron, using the function key to change the brightness did not yield any results. Brightness was at the maximum and my attempts to lower it went in vain.

It turns out, there are two bugs related to brightness issue in Ubuntu. One relates to Nvidia graphics card and other relates to Intel graphics card. The solution, that worked for me, is for Intel one. Let’s first find out what graphics/video card to do you have.

Find video/graphics card in Ubuntu and Linux Mint

Run the command below in terminal to know what video card is used for the backlight/brightness:

ls /sys/class/backlight/

find graphics driver in Ubuntu

As you can see, the output for me is dell_backlight and intel_backlight. An indicator that the graphics card in use is Intel. Another way to find out the graphics card would be to go in System Settings->Details->Graphics. You can see the graphic card in use.

If your graphics card is Intel, you can proceed with the fix below.

Fix brightness control issue with Intel card in Ubuntu 14.04 and Linux Mint 17:

Open a terminal and create the following configuration file, if it does not exist:

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

Now we need to edit this file. You can use any editor be it a terminal one or graphical.

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

Add the following lines to this file:

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

Save it. Log out and log in back. The brightness control should be working through function keys now:

Fix brightness control not working in Ubuntu 13.10

If you find that brightness is reset after restart, try this to fix brightness settings not remembered by Ubuntu and Linux Mint.

That’s it. I think it’s one of the must to do thing after installing Ubuntu 14.04. If it worked for you, you may also try some other small tweaks related to Ubuntu 14.04:

Did it work for you? Let me know if you have questions or suggestions.

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  • steven

    Thanks for your tutorial Abhishek, it is work for login and logout, but it doesn’t work if you shutdown your computer and login to the system again. Can you give me more option how to make the brightness work permanently ? Thanks.

    • Abhishek Prakash

      Thanks for update. In fact I did not check after shutting down. I’ll try again once I go back home and will update the tutorial with a ‘permanent’ solution.

      • sick6oy

        Have you found a solution to brightness work permanently ?

    • Abhishek Prakash

      Working for me even after reboot.

    • sick6oy

      I have this problem too. After reboot I have to again adjust the brightness level.

  • steven

    hmmm, it is strange… maybe the option like

    Identifier “card0″
    Driver “intel”
    Option “Backlight” “intel_backlight”
    BusID “PCI:0:2:0″

    have different configuration between us. Can you give me clue how to get that value, so I can adjust in my system. I am using elementary Luna 0.2 FYI. Thanks in advance.

    • Abhishek Prakash

      What’s the output of this command:

      ls /sys/class/backlight/

  • Reza

    Amazing! It worked for me perfectly on Thinkpad Edge 15 even after reboot. Thanks Abhishek.

    • Abhishek Prakash

      Welcome :)

  • Jbal Tero

    AMAZING! It WORKED for me after so many research!. Sony VAIO VPCEG2AEN.

    • Abhishek Prakash

      Glad that it works for you :)

  • Ashok

    i am using Linux mint 16, and is there a possiblity of reducing brightness beyond the function keys can key can provide?
    even in full dim, its too bright for my eyes. Help me out..

    • Abhishek Prakash

      I think yes, you can change the configuration to tweak the brightness level. I’ll find out once I get back to my home computer.

      • parkcity

        can you please tell me which file to change for additional dimming

  • vikash singh

    ty ty worked very well

    • Abhishek Prakash

      welcome Vikash :)

  • Henrique Campos

    It worked on sony vaio svt1411bpxs. Thanks!!

    • Abhishek Prakash


  • Deepak

    Thanks it worked for ubuntu 14.04 upgrade from 12.04

    • Abhishek Prakash

      You are welcome Deepak.

  • Somasundaram Mahesh

    That’s awesome fixed brightness issue on my laptop after years…!

  • Ikhsan Agustian

    works on my 14.04 fresh install


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  • ExitEden

    Worked for me in 14.04 on a Lenovo V570. Thanks for posting this!

  • Kevin

    Not working for me :(
    After doing all of that, when I reboot my system I have a beautiful black screen. It’s like my screen wasn’t even turned on… strange.

    My graphic card is an hybrid intel + ATI mobility radeon 5470 (tricky card, this one). Any ideas?

    • Kevin

      I forgot saying, I’m in Ubuntu 14.04

    • Muhamma Gelbana

      The same happened to me. To fix this, you have to boot to recovery mode. Which is, when the grub menu appears, don’t choose to boot to ubuntu, there is an another entry that should look something like “Advanced options” or “recover mode”, choose that, then a menu will appear, choose to login as root. Now you have root access to your system but all your disk is mounted in read-only mode. To remount it in a writable state, type the following command “mount -o remount,rw /” then delete the file you created, restart you system, search for another solution and when you find one, please do tell :)

  • dtelaroli

    Work fine in Dell Vostro 3560.

  • Curtis

    Thank You, so much. My computer was to light and couldn’t see display well. This fixed it.

  • Bharath

    Thanks a lot! The brightness control works now on my Dell Inspiron 15 (3537) with Ubuntu 14.04 on it.

  • Hiro

    Does not work for me. Using Kubuntu 14.04 on a HP Pavilion 14″

    I’ve added acpi_osi=Linux to Grub, and fn keys work for volume, but it’s always pressed, it doesnot release :/

  • christer247

    This is great if you have intel. But I’m having the EXACT same problem with Nvidia Quadro!!! :( Can someone please tell me how to fix it so the FN brightness keys actually changes the brightness? It was only AFTER installing the proprietary Nvidia driver that this problem occured, before with the Nouveau driver I could change brightness without problems.. Also there’s an ugly Nvidia logo screen popping up for about one second during boot right before the login-screen. Can someone help, or point me in any direction please? :)

    • hbhh

      nvidia-331 and prime

    • Abhishek Prakash

      I have no experience with Nvidia. Perhaps some other readers have a trick.

  • Darter

    Dosn’t work for me :(

    user@Darter:~$ ls /sys/class/backlight/
    acpi_video0 intel_backlight

  • Vinay Kumar

    I get this error when I try to create a configuration file

    “touch: cannot touch ‘/usr/share/X11/xorg.conf.d/20-intel.conf’: Permission denied”

    I couldn’t also create a file using gedit in that particular folder as it shows “Permission denied” when I try to save.

    Please help.

    • Abhishek Prakash

      Try the same command with sudo before it:
      sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

  • Black_Cat_PL

    On Dell 14z (N411z) dosn’t work too…

    for command: ls /sys/class/backlight/ —–> I get this answer:
    acpi_video0 intel_backlight

    How to fix this bug? Some body please help…

    • Dario Jimenez

      i have the same problema, have you fix that?

    • rpgmaker

      Same here, have any of you found a fix to this problem? This was working fine up until 13.04. I don’t know what they messed up after that that screwed up this.

    • Postadelmaga

      Any one found a solution for N411z ? the issue looks to be an regression in the kernel module that manage the Dell hotkeys …

  • Marco Gonçalves

    Perfectly, thanks

    • Abhishek Prakash

      welcome :)

  • sumit

    worked like a charm!!
    i upgraded to ubuntu 14.04 yesterday and was not quite sure what the problem was. Can you please explain a bit more on why this happens though?

  • Muhamma Gelbana

    This broke my system but I managed to recover. How can I confirm that my APU (Intel graphics integrated to the processor) is actuall card0 and not something else ?

    • Abhishek Prakash

      Thanks for the recovery steps Muhamma. It will surely be useful for other readers.

    • Amar Prabhu

      It broke my system Xubuntu 14 as well.

      acpi_video0 intel_backlight

      I did the same things as you did, came back to report – and same comment.

    • Amar Prabhu

      Found the solution. Update your Grub file in /etc/default/grub to

      GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor”

      update grub using the command


      Reboot and you are done.

    • Kai

      “…type the following command “mount -o remount,rw /” then delete the file you created”
      How do I delete the file?

      • Muhamma Gelbana

        rm /usr/share/X11/xorg.conf.d/20-intel.conf
        cd /usr/share/X11/xorg.conf.d
        rm 20-intel.conf

        • Felipe

          In my case none of the options deleted the file, when i tried with the first you put, the systems says “it can be deleted system of archives of only lecture” and the 2d option says that doesnt exist the archive or directory plz Help : /

          • Muhamma Gelbana

            Have you ran this command first ?
            mount -o remount,rw /

          • Felipe

            Yes I started with that command but got the results indicated. : /

          • Muhamma Gelbana

            Try browsing to the directory so you only need to specify the filename and not the full path. I don’t know how else can this be solved :/

          • Felipe

            Muhamma, finnally the problem was solved, I still cant use the brightness control but my laptop resurrected, it seems my problem was an error in tipying one of the commands line : /

          • Muhamma Gelbana

            I’m very glad it worked !
            I hope Linux will have better graphics support in the future. I love Linux and I hate to go back to windows again.

          • alexgo

            It also messed up my computer and it wouldn’t boot. I was worried I would have to do a clean re-install, but this fixed it, thanks!

            Now if only I could find a working solution to turn down the brightness and save my eyes.

          • Muhamma Gelbana
    • Thanos Tsikerdekis

      You saved me! Thank you!

    • Sriram Puttagunta

      How do i delete the file??

      • Muhamma Gelbana

        rm /usr/share/X11/xorg.conf.d/20-intel.conf

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  • Raj

    Thanks, this worked perfectly! I had tried modifying the grub conf before, and that fixed the brightness but had the undesirable effect of causing the system to freeze. Your solution finally did the trick.

    • Abhishek Prakash

      Welcome Raj.

  • Malik

    Thanks Abhishek it worked for me “Linux Mint 16 Cinnamon 64 bit” on Dell inspiron 15 3521

    • Abhishek Prakash

      Thanks for the info that it works on Linux Mint 16 as well.

  • Lazlo

    XUbuntu 14.04 : It works !

  • Amar Prabhu

    For those who this fix did not work (it didnt for me), do the following:

    Update your Grub file, line no 11 in /etc/default/grub to

    GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor”

    update grub using the command


    Reboot and you are done.

    • Sumi

      Hi Amar,
      this worked for me like a charm.


      • Amar Prabhu

        Cool. Glad it helped.

        • jbase78

          worked on my acer aod257-1471 netbook. Thanks Amar!

    • kai

      Thank you, this worked for me. The font seems weird though.

    • Sycokinetic

      I didn’t run update-grup yet, but editing the file and rebooting seems to have fixed all of my function keys. I’m not sure why adding acpi_backlight=vendor would affect more than the backlight, but for now I’m not complaining. :)

    • John Weland

      Great work, now I just need to know what commands to use for my shortcut keys.

    • ANG

      I edit the text, but when I go to save it I get an error “Can’t open file to write” Any suggestions?

      • Amar Prabhu

        Check your permissions.

        • ANG

          Permissions were checked. I spent a few hours trying to find why it wasn’t working when all of a sudden everything clicked and came into play. The fn keys work great now. Thanks!

      • Abhishek Prakash

        Try to put write access on the file

    • Adam

      how do i edit it

      • Amar Prabhu

        VIM or any other editor. Open it with Super User permissions.

    • Bernardo

      The best solution I have found.

    • Juan

      Thank you Amar!

    • xsoultribex

      i have this kind of set up but its not working in fn

    • Shubham Rajdhar

      Thanks my savior! 😀

    • Anu

      works great!!! Thank you

    • Amitava Sutradhar

      not working for me.

    • Thomas

      Thank you so MUCH! I’ve been wrestling with this for months!

    • ShiryuDragon09

      THANKS !!!

    • Luciano

      I’ve upgraded Linux Mint from 13 to 17 and 17.1 and the brightness control stopped working.
      Then I spent days trying to make it work again, and your small and quick hint solved my problem !

      Thanks a lot !!!

    • Xi

      There is a major question which no one asked you here. Let me ask you.
      Your fix works partially. The fn keys are working with brightness. But after every reboot, it gets to maximum/too low on different systems. There are fixes for that as well and most used is However, if we set the brightness to a fixed one. If we want to change the brightness again, do we need to run the steps in above link again? Or if we change the brightness using fn keys, it’ll be set as default automatically?

    • Motta

      Thanks This worked for me :-)

    • Motta

      Thanks This worked for me :-)

    • Jbott

      If you are on Ubuntu 14.04 with a kernel 3.13 or later, instead of acpi_backlight=vendor try instead:


    • Cameron Martin

      Why do hardly any of the ‘fixes’ to Ubuntu bugs ever say how they work? I don’t like blindly following instructions, especially involving editing my bootloader configuration.

      • Cameron Martin

        On second thoughts, maybe this comment seems slightly hostile. What I should have said was, “How does this work?”.

    • alexgo

      After I change line no 11 do I close the window? When I try and close the windows it asks to either close without saving, cancel or save as. If I do save as, what do I name it? It won’t let me replace it with the old file.

      I also tried leaving the window open and doing “sudo update-grub” in the terminal, but that doesn’t seem to change anything.

      • Amar Prabhu

        Please open the editor in ‘superuser’ mode ‘sudo gedit filename’

        Or do it in ‘sudo vim /etc/default/grub’

        • alexgo

          Thank you it works! My eyes are now saved!

    • Dexito

      i did this. it worked, my screen’s brightness went lower. but i still can’t adjust my brigthness. my Fn. key still not working. i’m using ASUS X401U with trusty tahr inside

  • Manoj

    Awesome. Thanks yaar…

  • eaglgenes101

    What about those that jumped the gun and installed mir?
    Same procedure? Or do I work with the mir files instead?

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  • Bruno

    Works in Latitude 3540!

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  • petra

    thanks, works great for Dell Vostro 3560 and Mint 16

  • Vitor

    Wow, Linux is so intuitive, it amazes me, ugh.

    Anyway, this fixed the problem for me, thanks.

  • Dumas V

    This did not work for me. When I added the code mentioned above, I get a black screen and will not boot back into Ubuntu. Also, since this is a clean install when booting before this, I have never gotten a screen to allow me to select recovery mode, it normally just boots in Ubuntu from turning on the machine.

    Is there anyway to recover without having to install the OS again?

  • Anto

    thanks a lot, it works 😀

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  • mkrooted

    Thanks very much! It works!

  • fero bernath

    hi guys, this initially broke my Ubuntu 14.04 installed on Packard Bell EasyNote TX86 because the firs quotemark is superfluous. Correctly it should read:

    Section “Device”
    Identifier “card0″
    Driver “intel”
    Option “Backlight” “intel_backlight”
    BusID “PCI:0:2:0″


    Once I corrected the entry, all is OK and the hardware buttons for screen brightness work like a charm. Hope it helps.

    • Abhishek Prakash

      Hi Fero,

      If you copy paste it, the first ” will not appear.

  • Angalan

    Doen’t work even for me…
    Samsung NP900X3D

    for command: ls /sys/class/backlight/:
    intel_backlight samsung

  • ameer

    amazing! thanks a lot man, thank you so much!

    • Abhishek Prakash


  • monika

    couldn’t do.. this is coming -> “touch: cannot touch ‘/usr/share/X11/xorg.conf.d/20-intel.conf’: Permission denied ” after entering this “touch /usr/share/X11/xorg.conf.d/20-intel.conf”.. help me asap..

    • Abhishek Prakash

      try sudo before it. I am editing the article.

      • monika

        thanks .. 😀 it worked 😀

  • monika

    i hv ubuntu 14.04

  • Aniket

    for lenovo z570 and similar use ” echo 150 > /sys/class/backlight/intel_backlight/brightness ” in terminal with root access.

    For diffrenet brightness, change 150 to any othe number (ex. replace 150 to 250 for more brightness)

    • Abhishek Prakash

      Thanks for sharing Aniket. I hope it works for many.

  • Lyes Alger

    waw its ok for me thx a lot

    • Abhishek Prakash

      glad it helped you

  • Ali Rıza Şahinkaya
    • Abhishek Prakash

      The link is not in English but it may help someone. Thanks.

  • nicolausgr

    Great! It works perfectly on a Dell Inspiron with Intel Graphics card & Ubuntu 14.04. Thanks!

    • Abhishek Prakash


  • Martin

    Finally!!! Thank you for this solution! I updated my eeepc from Lubuntu 13.10 to 14.04 and suddenly the brightness problem appeard. But with the configuration file:

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

    Now we need to edit this file. You can use any editor be it a terminal one or graphical.

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

    Add the following lines to this file:

    Section “Device”
    Identifier “card0″
    Driver “intel”
    Option “Backlight” “intel_backlight”
    BusID “PCI:0:2:0″

    It works!!!! Thank you!!!!

    • Abhishek Prakash

      Welcome Martin :)

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  • Mohamed Semlali

    It works on 14.04.

  • lemming

    great work, dude! After searching for a solution on my eeepc 1215n (editing grub didnt work) for days (cummulative) you finally brought light to me (shining through my screen into my face now)! thanks alot, man!

  • Redga

    It worked lika a charm!! Thank you so much.

    Every time that I power on, the brightness is at full, is there any way that the system “remembers” the level of brightness in which I power it off?

  • Howard

    it works for me. Thanks!

    • Howard

      btw my model is lenovo w540 ubuntu 64 trusty

  • snaprails

    You Star! Worked a treat on Packard Bell Easynote TJ65. Lack of brightness control had been annoying the hell out of me since install :-)

    • Abhishek Prakash


  • Prashant

    Thank you very much !!

    • Abhishek Prakash

      welcome Prashant

  • ishan bakshi

    hi, i could not find the 20-intel.conf file in this location: /usr/share/X11/xorg.conf . My graphics driver is “Mobile Intel® GM45 Express Chipset x86/MMX/SSE2″. Any suggestions plz ?

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  • jeremy5321

    Some using ubuntu 14.04 and LM17 might need to add video.use_native_backlight=1

  • shthek

    worked like a charm for me. Thanks!

  • Pingback: Ubuntu 14.04 Intel Brightness After Resume - Tech Forum Network()

  • lucky

    Worked for me, thanks!! Lenovo z570 with Ubuntu 14.04.

  • ubermook

    You are a genius! I had been searching for a solution for this for so long and it has worked. Now I can use my Lenovo b570 with Linux on battery. At last. Thank you!

    • Abhishek Prakash

      Welcome ubermook :)

  • WayOutt

    Man!THANKS!!!!Lenovo v570 (i3 2310 geForce 525,OpenSuse Tumbleweed) works with xorg & grub flags.

    • Abhishek Prakash

      Welcome :)

  • Jilguero ostras

    Thank you very much. It also works on Ubuntu 13.10.

    • Abhishek Prakash

      You are welcome Jilguero

  • Vahe Sahakyan

    Hi, thank you very much.

    Perfect solution !!!!

    I have same problem with my HP Probook 470g0. with the graphic card Intel® Ivybridge Mobile.

    It’s works and fixed the issue.
    Thank’s again

    • Abhishek Prakash

      Welcome Vahe :)

  • Mihai


    Had the same issue on a HP Probook 4540s – Ubuntu 14.04.

    Problem solved!

    • Abhishek Prakash

      Welcome Mihai

  • Seji

    Works perfectly on Linux Mint 17 @ ASUS UL80-VT

    • Abhishek Prakash

      Glad to hear that :)

  • gomaaz

    saved my day on Xubuntu 14.04 64bit. Thanks!

    • Abhishek Prakash

      good to hear that :)

  • Gleise

    Thanks a lot! I just upgraded my Ubuntu 12.04 to 14.04 and had no idea what was happening. Your post saved me a lot of time.

    • Abhishek Prakash

      Welcome Gleise

  • John Weland

    So I followed this tutorial and it didn’t work… at first. I then followed the “featured comment” by Amar Prabhu and my brightness control DOES work now via slider however I still have to setup my shortcut keys and I’m not sure what command I need to send on the hotkeys to make it work.

  • ANG

    Abhishek, I can create the file but when I try to edit the text and save it I get an error that I don’t have permissions to do that. I’m on 14.04. What would you suggest?

    • Abhishek Prakash

      Did you try sudo?

      Also, can you put the write access on it using command line:

      sudo chmod u+w /usr/share/X11/xorg.conf.d/20-intel.conf

  • jk

    Thanks, work fine for me. Ubuntu 14.04

    • Abhishek Prakash

      welcome jK

  • Dan

    Awesome! Thanks

    • Abhishek Prakash


  • ミチャルド

    Thanks! It worked at the first try! 😀

    • Abhishek Prakash

      welcome :)

  • esculapweb

    thanks! it works for me and now my eyes can work again)

    • Abhishek Prakash

      welcome :)

  • Kuro

    Has any one figured out a legit way to fix the brightness issues on a computer that has an Nvidia graphics card? Because I have been looking around for a while and I haven’t had any luck…..

    My graphics card as stated in my detail: GeForce GTX 660M/PCIe?SSe2

  • Hnizil Mehdi

    thanks lot .

    • Abhishek Prakash


  • Michael Garofano

    The standard fix on this page worked HP 8440p, Xubuntu 14.04

  • kinjal

    It worked for me. I installed Ubuntu 14.04 on Dell Inspiron series laptop and lost brightness control function. Got your steps fix this problem at first attempt. Thanks

    • Abhishek Prakash

      You are welcome Kinjal

  • Kevin

    Many thanks, worked on my Samsung S3510 Laptop with Mint 17.

    Just make sure you don’t copy the first “

    • Abhishek Prakash

      It shouldn’t be copied. Its just themes that puts ” before quotes.

  • Kaushal

    Worked perfectly on Acer Aspire V3 on Ubuntu 14.04 with Intel® Ivybridge Mobile. Thanks! :)

    • Abhishek Prakash

      Welcome Kaushal.

  • jonah

    thanks dude, worked perfect on my sony vaio

    • Abhishek Prakash

      Welcome Jonah

  • tim lion

    fuck yeah!
    worked for me, thanks mate…

    • Abhishek Prakash

      you are welcome Tim :)

  • anom

    Not only did this not work, but the limited information given in this tutorial caused me to ruin the graphics driver. Now mdm will not start. Thanks a lot.

    • Abhishek Prakash

      you can revert the changes from the command line at login and reinstall unity again.

  • parkcity

    Thanks works great!! is therea way to dim even more? can you please tell us which file to configure?

  • aby337

    works great..THANK YOU :)

    • Abhishek Prakash


  • Alaskan

    thank you :)

    • Abhishek Prakash

      Welcome Alaskan..

  • Orestis Gorgas

    The article method worked for Inspiron 15 3521.

  • Tsvetelina

    Thank you it worked! :)

    • Abhishek Prakash

      Welcome :)

  • xsoultribex

    20-intel.conf i dont have this kind of file.. can you tell me why? im using ubuntu 14.04 LTS kernel generic

    • Abhishek Prakash

      You’ll have to create it.

  • Ati Rosselet

    worked for opensuse 13.1 on vostro 3560 w/radeon+intel
    Thanks – now I have screen brightness control back!!

    • Abhishek Prakash

      Welcome Ati :)

  • Thejas

    Thanks for the blog. Brightness settings were configured successfully on my dell intel laptop.

    • Abhishek Prakash

      You are welcome Thejas

  • Venk

    it worked !!!

    • Abhishek Prakash

      Welcome Venk

  • guestname

    Worked for my Asus UL50VT w/ Mint 17! Thank you very much, I’m surprised that it was so simple to fix yet nobody else had something that worked for me.

    • Abhishek Prakash

      Welcome. Things are often less complicated.

  • Karthik

    Hey thanks! It worked out well for me :)

    • Abhishek Prakash

      Welcome Karthik

  • Thatsme

    worked for my acer with Mint 17 and intel grafic

    • Abhishek Prakash


  • pongapundit

    It worked for me! I had problems with brightness control on Linux Mint 16 Petra running on Dell Inspiron 3537. I spent hours searching on net but none of the tricks worked including setting GRUB_CMDLINE_LINUX_DEFAULT. But This simple fix given here, that is, adding a “device” section to the 20-intel.conf file (followed by log out / log in back) worked like a breeze. Good job Abhishek!

    • Abhishek Prakash

      Welcome :)

  • gadgetboi

    i just don’t get it … it’s not working on my asus X200CA. first i somehow get error and could enter GUI, then i repeat it and could enter the GUI but even the brightness setting couldnt move (on the power setting) but somehow every function is working. and then i update the grub, this time the brighness setting on the power setting working but still no luck with the functon key :-( please help.

    • Zwitter69

      i’ve same issue with my asus x200ma
      tired ,want a solution!

  • gadgetboi

    you forget to mention to change line 12 from

    the Fn key works again but still it wont sync with the brightness setting on the power management setting … but it do the trick for now. let me know if you have solution for this 😀

  • uburoi

    Hello Amar,
    I had the same backlight issues with my 12.04 after updating to kernel 3.13, but creating the 20-intel.conf just did the trick. Thank you very much! (It works even better than before, because now the brightness steps are smaller so I can adjust the backlight more precisely.)


    Thank you very much! It does work for me – DELL VOSTRO 3560, Ubuntu 14.04.

    • Abhishek Prakash


  • RiddicK23

    Works for my HP Pavilion dv7 with intel HD Graphics 3000 with Linux Mint 17… Thanks!!!!

    • Abhishek Prakash

      Welcome Riddick23

  • esseafi

    Yes! Finally!! I have been trying to fix this all this week and this post was my solution. Thank you very much. – 14.04 on Intel PC

    • Abhishek Prakash


  • Ali Rıza Şahinkaya

    If you having trouble with bumblebee after applying this method.
    Solution is adding following lines to head of
    Section “Screen”

    Identifier “Default Screen”

    Device “DiscreteNvidia”


    • Abhishek Prakash

      Thanks for the tip. Hope it works for others.

      • Ali Rıza Şahinkaya

        I hope it works. In my case error messages;

        [ERROR]Cannot access secondary GPU – error: [XORG] (EE) intel(0): [drm] failed to set drm interface version: Permission denied [13].
        [ERROR]Aborting because fallback start is disabled.

    • Raphael Barros

      Tried opening Blender using it, the window decorations appeared, but nothing inside, the console showed this:

      libGL error: failed to load driver: swrast
      libGL error: failed to load driver: swrast
      primus: fatal: failed to acquire direct rendering context for display thread

      • Ali Rıza Şahinkaya

        I will investigate it. For me blender works normally.

      • Ali Rıza Şahinkaya

        Is virtualgl installed and bbswitch enabled?

        • Raphael Barros

          I tried again your fix on 14.04, and while it works, I can’t use my usb devices anymore, they’re not recognized…

          Now I’ll use Blender with my laptop’s touchpad, kkk, jk.

  • dj

    thanks a ton mate!!

    • Abhishek Prakash


  • Rubi Sharma

    Thanks .It really works..

    • Abhishek Prakash

      Welcome Rubi

  • Rajesh Nair

    How to Make it Work like Windows (auto Brightness When Charger is connected or Disconnected )

  • Viraj Nikam

    Thanks it worked great for me, the only problem is when I switch the brightness level to minimum the display goes completely dark.

  • Elad Avron

    Worked like a charm. Thank you!

    • Abhishek Prakash

      Welcome Elad

  • eioj

    thanks :)

    • Abhishek Prakash


  • Julien

    It works for Mint 17 on Toshiba R700 with an Intel graphics card.
    Thanks a lot!

    • Abhishek Prakash


  • Fibonacci

    Hey Abhishek! I have another related issue. I have nvidia 840M graphics card on my machine. But when i type in “lspci| grep VGA” in the terminal, it only shows the intel card. Isn’t ubuntu recognising my nvidia card?

    • Abhishek Prakash

      Hi Fibonacci,

      Your Nvidia graphics is not being used, at least for video. You may want to reinstall the Nvidia drivers.

  • Anand

    Thanks a lot mate. it did work for me

    • Abhishek Prakash

      Welcome Anand.

  • Abhay Mehta

    It didn’t work properly on my Sony vaio. Even after doing this my laptop giving me message like the system is running on low graphics mode and stopped at that point and did not start. Then I enter into single tty1 session and removed the 20-intel* file then I was able to start my laptop. So can you tell me the reason of this and give me the solution of brightness problem…

  • Diego

    Great thank you. It did work in my case (Xubuntu)

    • Abhishek Prakash


  • Nicolas Hasbun

    Thanks !! brightness buttons dont working was annoying me.

    Works like a charm now :)

    • Abhishek Prakash

      Welcome Nicolas

  • Ioana Pavel

    Thanks dude, it worked 😀 I am super grateful. Cheers.

    • Abhishek Prakash

      Welcome Ioana

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  • Mushik

    Thanks pal, it worked good :)

    • Abhishek Prakash

      You are welcome

  • nnnnnnnn

    this works on xubuntu thanks

    • Abhishek Prakash

      Good to know :)

  • nnnnnnnn

    toshiba portege z830/835

  • beofos

    I love you

  • Prantik Saha

    Thanks. It has worked for me. Nice work.

    • Abhishek Prakash

      Welcome Prantik

  • coolguest

    When I did ls /sys/class/backlight/ it didn’t return anything. I think I’m suppose to have the intel one because i have the integrated graphics.

    • Abhishek Prakash

      Which graphics card is in use at: System Settings->Details->Graphics?

  • harris

    about brightness i have grafics : Gallium 0.4 on AMD RV635 can i do the same thing as you said?

    • harris

      and my prossesor Intel® Core™2 Duo CPU P8400 @ 2.26GHz × 2

      • Abhishek Prakash

        I would NOT recommend it.

  • Erik Torres

    Thanks for the tip. It works for my Toshiba Portege with Sandy Bridge architecture and Intel graphics.

    • Abhishek Prakash

      Welcome Erik.

  • Armo

    the fix worked and now i am able to adjust brightness but fn + f4 & fn + f6 still dont work…any ideas?

  • vishwa2014

    Thank you so much the brightness control is working in my laptop.
    Thank you for posting thank you again.

    • Abhishek Prakash

      Welcome :)

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  • Randolph Lima

    Funcionou perfeitamente! Obrigado!

  • AMbro86

    How would I do this with an Nvidia card in my ThinkPad? I have a T61p with an Nvidia Quadro FX 570M. When I run the above ls command I get only one output though:


    Any ideas?

    P.S. I already tried the GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor” and it didn’t work. In fact it undid an earlier fix for my machine not shutting off completely.

    I’m on 14.04.

  • artgel dA

    thanks !

  • Ashok Naval

    please tell me how can i blacken the screen with shortcut key. e.g. i want to download something but want to study in front of laptop, so during that time i want to blacken my screen. in previous version of ubuntu, i used to do this with ctrl+Alt+L, but in 14.04 it just locks the screen and scree brightness is same. please help

  • frank

    Thank you Sir soo much. Work for me – I try Brightness Controller and nothing, but this is amazing! : )
    Just install Zorin 9 and control brightness on my Acer 5733!

  • Leandro Quibem Magnabosco

    It works, thanks!

  • Mikhail Cherepanov

    Thank You very much, solution with configuration file works perfectly on asus x551ma with 14.04.

  • HappyGuest


    GREAT !!! :o)

    Works with “Ubuntu 14.04 LTS”, live USB (UEFI boot), on “Acer Aspire E3-111″ with “Intel® Bay Trail” graphic chip onboard .

    Thanks !



    • Abhishek Prakash

      Glad you are happy Steve :)

  • Prakash Bala

    Works like a charm!!!! Much appreciated!!!

    • Abhishek Prakash

      Welcome Prakash

  • Sumudu

    it is work bro thank you very much !!!

    • Abhishek Prakash

      Welcome Sumudu

  • skyrohithigh

    Thanks, worked for me

    • Abhishek Prakash

      You are welcome

  • Sreekar

    Worked for me..thanks

    • Abhishek Prakash

      Welcome Sreekar

  • Kld Dlk

    Thank you very very much, you saved my eyes.

  • ByThe River

    Worked for me, thank you so much!

  • Donna

    Thanks for the brightness fix!

  • Arshit Aggarwal

    thanks for this solution….it worked for me !!

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  • Matt Ndk

    For all of you running a Laptop with NVIDIA Card and who are still not able to get the f* function keys for brightness to work, just follow the steps below. It worked very well for my system (Samsung q45, Intel Dualcore T7100 @ 1,8Ghz , Nvidia Geforce 8400M G 512) running Linux Mint 17.

    In command line, type in:

    sudo gedit /etc/X11/xorg.conf

    You will have to enter your root password.

    Now, you should see:


    Section “Device”

    Identifier “Device0″

    Driver “nvidia”

    VendorName “NVIDIA Corporation”



    If you see nothing, just enter all the lines above and follow up with the next step below

    Under the VendorName Line, add the following:


    Option “RegistryDwords” “EnableBrightnessControl=1″


    Now, save and reboot. Check your brightness controls, and hopefully this fixed things.

    I’ve tried so many solutions out of the net and nothing had helped me until I came to this solution. But be aware that these steps only working for NVIDIA Grafics and you must have chosen the NVIDIA Driver in your system in “Administration -> Driver Manager”.

  • caulk

    The fix worked for me, but it broke my USB mouse and touchscreen, as they are not being detected. But if I don’t apply the fix, brightness control does not work. Can anyone help me? Thanks.

    • Raphael Barros

      I also got the same problem, it’s almost unbelievable that a fix in a problem with gpu and brightness controls would lead to the computer not recognizing USB devices…

  • Zeke

    It worked for me, Ubuntu 14.04.1 LTS just a few minutes ago. Samsung N150P computer using Intel graphics. Good luck to everyone who has this problem, the solution worked perfectly for me!

  • Pingback: Brightness Control Not Working on Linux Mint | Danu Kusuma()

  • Emi Silva

    It worked perfectly for me! I’m using Lubunu 14.04 with a HP mini 110 3130br

  • roby

    Thank you Abhishek is working on my LENOVO e10 intel vga

  • Niraj

    Hey Thanks, this worked for me., yuppy…!!

  • twitudhay

    It worked.Thanks :)

  • Pawel

    Cool, works for me for dell XPS 15z on ubuntu 14.10.

  • Pingback: Solusi Kecerahan / brightness Tidak Berfungsi Di Ubuntu 14.04 LTS | Sang Bungsu()

  • tarun
  • Alfred Patric

    Dude, you are just so awesome, I have been trying to fix this for a long time now but this was such an instant fix to my problem!!! Thank you so much.

    PS: Is there any solution you have to sync music to iPhones in Ubuntu 14.04? I failed trying almost every given way. Thanks in advance!.


  • Rayan Hejazi

    I must say thank you. Thank you very much for the information provided. I am a subscriber to your email news letter and I am a fan user of linux (ubuntu, gnome,kde). I wish you the best. Have a pieceful life!

    • Abhishek Prakash

      Welcome Rayan

  • Vidmantas

    That was fixed my Sony Vaio brightness control isue .Thanks

    Open a terminal and create the following configuration file, if it does not exist:

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

    Now we need to edit this file. You can use any editor be it a terminal one or graphical.

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

    Add the following lines to this file:

    Section “Device”
    Identifier “card0″
    Driver “intel”
    Option “Backlight” “intel_backlight”
    BusID “PCI:0:2:0″EndSection

  • Dimitris

    fixed my problem on sony vaio, with opensuse 13.2

  • creatorb

    good one (y) i will try it on my ubuntu, i hope it works because i have try many solution on thread about brightness issue by changed some script but no effect on my laptop, i still feel dazzled. actually i have alternative simple way to get dark screen like but needed wine.

  • Sebastian

    Work Great thanks!

  • Ionut Popescu

    Thx mane, work!

  • webmakin

    it worked. Thank you. :)

  • ProfR

    Thank you man it was really useful and well described. Bravo !

    Have a wonderful day ! Cheers

  • Mike Chelen

    Fixed the problem on a Samsung N210 usin Xubuntu 14.10

    Anyone know what causes this bug? Has it been reported in the Ubuntu issue tracker?

  • Ezra Stein

    wow, thank you so much, it works!!!

  • daf182

    Brightness can be controlled with this setting. Ubuntu 14.04 LTS on HP Probook4340s

  • mada fakaing copy paste

    f.u.c.k you b.i.t.c.h now i cant get into ubuntu.

    aat the last line change this

    BusID “PCI:0:2:0″EndSection

    to this

    BusID “PCI:0:2:0″

    when you copy paste At Least DO copy properly

    now you fucked up my system.


  • El Tunguskano

    Man this works amazing! Even in a Macbook Pro in Live session!
    Thanks a lot. It’s convincing me, that ubuntu is definitely an alternative to use!

  • sylvain

    thanks for the solution, it worked perfectly for me on my Aspire E15 with Mint 17.1

  • adrian

    it works !great ! but when i restart my computer it return to maximum
    any solution for this

  • mar adrian belen

    it works !great ! but when i restart my computer it return to maximum Brightness:(. any solution for this

  • Abhinav Jha

    thank you sir…it worked…thank you very much…

  • muhammed hassan

    worked perfectly. thank you

    • Abhishek Prakash

      Welcome Hassan

  • shreejith

    Thanks your settings work; the grub edit did not work. The command is working with any icon just a square coloured box is coming

  • Khotso

    Sup people
    The edit works great but when you set the brightness control to its lowest the screen literally becomes BLACK(as in the p.c. has shutdown black) .How do you edit it to the pint where the lowest brightness is just bright enough?

  • yasin

    thanks it worked in linux mint 17.1. Great article

    • Abhishek Prakash

      Welcome Yasin

  • Enrico

    Works like a charm on Linux Mint 17.1 on Acer Aspire E3-112
    Thank you very much – I am happy now! :)

  • Mohamed Moftah

    Than you very much . It worked for me

  • Yann

    Thanks for these tips but alas! none of them worked for me.
    I own an ASUS Zenbook UX303LN-R4197H on which only the brightness Fn keys were not working (backlight and sound volume OK) under Linux Mint 17.1 64-bits. This laptop is equipped with 2 graphic cards (Intel HD4400 & Nvidia GeForce GT840).
    So for those like me, here’s the tip I found on Linux Mint Forums ( that worked:
    it consisted in updating the Grub file with this line
    GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi=”
    but not GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor”
    and uncommenting GRUB_CMDLINE_LINUX=””

    See attached pictures.
    Hope that helped.
    – Y

  • Jack

    This worked perfectly for me. Thank you.

  • Tyse444

    thanks so much for this! Worked perfectly for me and it was so easy!

  • John LaPierre

    Many thanks! Worked perfect.

    • Abhishek Prakash

      Welcome John

  • Revanth Korrapati

    Wow!!! Thanks a lot man!!

    • Abhishek Prakash

      Welcome Revanth

  • Malcolm

    Awesome post! I loaded Mint 17.1 on an old Asus 1001PX that has Intel video and sure enough the brightness controls were useless. This fix worked like a champ! Thanks so much for sharing!

    • Abhishek Prakash

      Welcome Malcolm.

  • romeof

    hi guy.. thanks for the post.
    anyway I try with my ubuntu 14.04 but ended up in low/graphic/mode.
    tryed to fix USING Recovery Mode through the recovery menu failsafx. With no avail.
    Can you give me a tip about how to delete the file I-ve inserted?
    it seems either failfax does not work and also I cannot open a terminal from failfax.
    hard time here .. that-s low/graphic/mode is driving me crazy.. :)

  • romeof

    hi there..

    I solved it. I was able to login to command line (with ctrl+alt+F1), I browsed to the new created file, deleted it and rebooted the system.
    I made a mistake copying the code.. made a typo…
    all the best,

    • Abhishek Prakash

      Glad that you were able to figure it out :)

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  • Avi

    “sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf”

    when I run this, a blank page is displayed..

    • Abhishek Prakash

      because the file has nothing in it or perhaps it doesn’t exist. You’ll have to create one and add the lines in it.

  • Asad

    worked perfectly for my Linux Mint 17.1

  • Sonny Parlin

    Worked like a charm, thank you!

    • Abhishek Prakash

      Welcome Sonny

  • Jason de Souza

    Thanks! This worked for me like a charm on Manjaro Netbook Edition. :)

    • Abhishek Prakash

      Thanks for verifying it on Manjaro.

  • Suranga Premakumara

    this is working for me. ubuntu 14.10 virsion . thank you.

    Open a terminal and create the following configuration file, if it does not exist:

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

    Now we need to edit this file. You can use any editor be it a terminal one or graphical.

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

    Add the following lines to this file:

    Section “Device”
    Identifier “card0″
    Driver “intel”
    Option “Backlight” “intel_backlight”
    BusID “PCI:0:2:0″

    Save it. Log out and log in back. The brightness control should be working through function keys now:

  • Daniele Segoloni

    Hey, thank you! it worked on my Acer Extensa 2509. Anyway now I have the brightness commands inverted (if I try to increase the brightness, it decrease, and viceversa). Not a big deal, but maybe someone can help me to set it in the right way..?

  • Everest

    What about those witha a Nividia driver?

  • bob

    thanks worked for me

  • rohin

    i have dell inspiron 15r, intel graphic, ubuntu 14.04. worked for me. thanks !

  • Siva

    The fix works only partially. I see the brightness applet’s slider moving from the left to the right. However, the screen does not brighten or dim. I am a newbie on Lenovo z570 with Geforce 520M.

    The output of ls /sys/class/backlight/
    acpi_video0 acpi_video1 intel_backlight

    The entries in my grub config (except the Ln: xy =entries) are,

    Ln: 11 #GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”
    Ln: 12 #GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor”
    Ln:13 GRUB_CMDLINE_LINUX_DEFAULT=”quit splash video.use_native_backlight=1″

  • Siva

    Learnt the following command from another website and it works like a breeze.

    sudo tee /sys/class/backlight/intel_backlight/brightness <<< x
    sudo tee /sys/class/backlight/intel_backlight/brightness <<< x

    x in the command is the value of my screen's brightness. However, this is not linked to the function keys. How do i achieve this ?

    Thanks in advance for your help. :)

    • Siva

      Lot of tinkering and many inputs from experts from various websites. The following line in grub config /etc/default/grub finally worked for me.

      GRUB_CMDLINE_LINUX_DEFAULT=”quite splash acpi_osi=Linux acpi_osi=’!Windows 2012′ acpi=force acpi_enforce_resources=lax drm.vblankoffdelay=1 acpi_backlight=vendor video.use_native_backlight=1″

  • soufya

    it didn’t work for my vio, but I fixed my eye problem with putting on my sunglasses

  • paul

    Worked perfectly for me! Thank you!!!

  • lastnewbie

    Me funcionó con Linux Mint

  • ykgoon

    Had the same problem with my Ubuntu 14.04 on Lenovo G40-80, this worked for me. Thank you.

  • Wael

    Thanks!! It works very well on Samsung NP N145 Plus, under Ubuntu 14.04…

  • Lesedi

    Lol, the primary fix worked for me but the brightness adjustment works backwards i.e high is low and low is high both on settings and using buttons

  • fabsxm

    If anything works, the last thing and maybe should be the first one to do is uninstall FGLRX.
    After that and read lot of forum I did it and my backlight works fine.

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  • observation

    Thank you for your solution.
    My system: Ubuntu 14.04 32-bit

    Graphics: Mobile Intel GM 45 Express
    This trick worked very well in my case. To make it work, the system needs a restart, not only a user log off.

  • Bayleef

    Acer 5332 laptop Ubuntu Gnome 14.04.
    Creating config file 20-intel.conf as above gave me a blank lit screen on reboot and I could not log in :( I had work out a way to delete the file before I could reboot my system!
    This method works however:

    sudo gedit /etc/default/grub




    GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor”

    sudo update-grub and reboot

    Backlight keyboard controls then work! Many thanks to all who worked on all these fixes!

  • Azzam SA

    -[asking help] [asusx401U] [Brightness error]

    –hai abhishek and
    amar prahbu,i really want to install ubuntu on my brother laptop,
    before he is running windows 8 ,and all working fine,but when I try
    to install ubuntu ,the fn keys doesnt work and I try what amar prabu
    said,it just help me little, I can reduce the brightnes using amar
    prabu way,but the light still so shine,.

    – I want to make the
    brightnes working fine as my laptop asus x201e,i can reduce the
    brightnes 16 times or level,but on asus x401u ,its just work 2 times
    or two level,so the light still very shine.

    help pelase,

    thanks for advance.

  • Andronikos

    I don’t know any code, i’m completely new to linux. After 2 weeks of trying out all the solutions in found in fora, I found this bypass; Set your resolution with the function button BEFORE Ubuntu starts up :D. I’m quite sorry for not giving a real solution, I’d really like to contribute to free stuff but this is satisfying enough for me, I have to press esc anyway or it won’t boot.

  • aadi

    thanks a ton!

  • Manish Kumar Bisht

    I did this and after logging out, GUI is not working for me. Its just a blank screen. I tried booting through recovery mode but hell, It is not logging me in(in terminal) even when I am entering the correct log in information. At this stage also if I try to switch to GUI mode(by pressing Ctrl+Alt+F7) it leaves a blank screen. What should I do?

  • Justice Mba

    Hey you the best!!!! Just the way it should!

  • ozer

    After I did this I got this error “The system is running in low-graphics mode”. How can i fix this now?

  • NewUbuntuUser

    It worked with my Gateway ID49C07u laptop with Intel graphics. Thanks a lot.

  • Chris

    THANK YOU! I tried to fix this for ages and did so many unnecessary things, including flashing my BIOS. You are more legendary than Hercules.

  • Dexito

    what if i’m using AMD?
    i’m using AMD for all chipset including graphic n my Trusty Tahr i386

  • Jenny Haston

    Perfect. Thanks so much, it makes a big difference!