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[SOLVED] Brightness problem in Ubuntu 12.04 Precise Pangolin

Well my friends have been facing brightness problem in Ubuntu 12.04 Precise Pangolin. And every one were facing and asking me to help me out with it. So, I viewed all over the Internet and helped them out. I helped with it myself too in Dell XPS 13. And for friends Acer Aspire, HP Pavilion DV6. So it might work on most of all the PCs.

My friends were just trying the xrand solution that just decreases the Contrast which had no effect on the power consumption. So, this solution was the most to be kept. I am feeling quite when the Fn(Function key) and the Brightness Up and Down are working great. You can follow up the procedure that I have kept in an easy steps.

Open terminal ( Ctrl+Alt+T ) and type:

sudo gedit /etc/default/grub

You will find this line in the new opened window:

Change it to:

Save and close the window and type this in the terminal:

sudo update-grub

This will update your grub and while rebooting your PC, it will set an extra parameter on the grub menu during boot. This problem might have occur on due to the upgrade on kernel.

Enjoy the power saving system.

  • JC00002


    I tried the above changes to try and fix the brightness problem and it did not work. I have a Dell XPS L702X.

    Still the same problem of not being able to adjust the brightness even after implementing the changes.

  • harsha

    tried this on my vaio…nothing happened 🙁

    • Really? But my most of the friends are good with this but I couldn’t test on Vaio cause non have that one 🙁

  • Alex Smirnov

    It works with HP dv6-6b53er (i5 2430m + 6770m). Thank you.

  • Chris

    Thank You a lot! It works fine on a Toshiba Tecra M11 running Ubuntu 12.04 64bit. 🙂

  • Sitansh Rajput

    Thank you so much. Worked on my DV6TQE 6100 CTO. Although I have a system error reporting something along the lines of gnu_color?

    • I am not sure about that. Never faced that problem. Will try to replicate that problem. Try reporting on Ubuntu they will provide a simple Kernel Patch next time on the Synaptic updates.

  • sumbody

    it helped inna HP 450 as well
    i added acpi_osi=linux and the brightness n volume keys (those that works pressing Fn key) started working too

  • Quipman

    Thank you I tried your solution and it worked on my Toshiba L305-s5919 laptop.

  • DON


  • Ivan

    Not working on Toshiba L855.
    This setting even removed the backlight controller from the system settings, and I can’t do anything with function keys.
    Any ideas about what value I could use instead “vendor”?

  • This solution worked great on my HP pavillion DV6 laptop running ubuntu 12.04. Thanks!

  • Sven Svensson

    After sudo update-grub, I get

    “/usr/sbin/grub-mkconfig: 11: /etc/default/grub: splash: not found”

    Any thoughts?

    • I am not quiet sure but why have you done grub update?
      in the Above post please note that the auto ” is somewhat changed so the error occurs. Please correct the “Quote” thing to the original quote.

  • Jordan V.S

    Thank you!!!!!!

    It helped me to solve a problem that I thought was insoluble

  • Works like a charm with my Notebook LG R580 and Ubuntu 12.10… THANK YOU!!! 😀

  • Martin Wildam

    Indeed battery indicator also shows now much more time remaining – we will see if it keeps to promise. 😉

  • me

    Thank you very very much!!!

  • Adolfo

    Thank you so much…it work for Lenovo Z360

  • Angel

    Thanks!! I’ve been trying to solve this problem and only this works on my Gateway M-Series.

  • SpoK DZ

    thanks 🙂 work with acer aspire 5742

  • damystica

    3 words: Oh My Goodness!

    After all the stupid stupidest stupidier workarounds in rc.local and LMT, all it took was adding simple: quiet splash acpi_backlight=vendor to grub! From now on, any increase/decrease in brightness through user interaction is kept…NO MORE RE-ADJUSTING! Woohoo!

    You, my man, are a Ubuntu Savior! I believe this change will work on most laptops with Intel HD3000+

    Thank you and thanks God!

  • Ivan Huerta

    YES!!! Thank you so much!!! on my HP Pavilion dv6 (w/ Beats audio)

  • This solved my problem in half. My brightness was just out of control and I could not control it at all and the computer was working really hard. Now I can control the brightness bar, the computer does not get crazy anymore, but the brightness does not change. It’s at the minimum.

    • Ok, that must have solved the problem. Wait for the latest update of kernel and hope for the best. If available, try updating with Kernel 3.9 if you want some fun.

  • Guest

    Can’t open “sudo gedit/etc/default/grub”.
    error: command not found
    please help

    • you forgot the “” the command looks as:
      sudo gedit /etc/default/grub
      you mistakely typed “gedit/etc/default/grub”

  • not working on acer 5750.. plz help

    • What exactly does it shows or what exactly happens?

      • I changed the line in grub. Updated it but still not working. i’m not getting an errors, it just not working.

  • brizio♣

    Doesn’t work on Asus a55vd. The combinations fn+f5 and fn+f6 are just dump now.

    • If any problem occured, you can just restore the default file and update the grub again to get everything back.

  • Ge

    It works on Packard Bell dot s!

  • Steve

    NICE! Works on Dell Studio 1745

  • David Johnson

    Thanks very much for this solution! It worked on my Gateway NV57h44u (Intel HD 3000 graphics). Much appreciated!

  • Tom Cloons

    Top notch! Success on a Samsung NC210! Thanks for the expertise!

  • Sadly, this fucked up my Dell Inspiron 15r 3521 > Ubuntu 12.04 stuck in boot.
    “end_request : I/O error, dev sda, sector xxxxxxx”

  • Maksim Dmitriev

    It almost works.
    Laptop: Asus UL80VT
    Ubuntu: 12.04.3 LTS
    Kernel: 3.8.0-30-generic

    I have to reboot after changing brightness. No effect without rebooting.

    • Yes you obviously need to restart your laptop 🙂 good to hear it worked

      • Maksim Dmitriev

        I mean the Fn + Brightness Up/Down keys don’t work properly. I adjust the brightness, and it takes effect only after rebooting. So, modifying Grub is not enough in my case.

        • That’s a strange case I have seen. Actually how do you adjust your brightness?

          • Maksim Dmitriev

            I erased GRUB and restored it again because Windows restarted right after its logo had appeared. I thought Ubuntu had caused the issue. But it didn’t.

            After all, I can adjust brightness through settings. If I press Fn + F5/F6 (Brightness Down/Up), nothing will happen. It’s strange, but adjusting through settings suites me.

            The line:
            GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor”

  • justin quach

    what buttons are for brightness up/down?

  • 5TUFF

    Thank you a lot ! That bright light just hurt my eyes, now its just perfect !

  • john


  • nemohacks

    Great Man..you saved me..


  • Scoud

    After applying this and rebooting. I was stuck with error messages about READ FPDMA QUEUED. I managed to fix it in recovery mode by undoing this. Very strange!

  • Nirag Madaliya

    supreb and worked no softwar are need you rocking man

  • 1544C

    Works fantastic with Gateway M-6804m Notebook, thank you so much.

  • Luiz Rogério de Carvalho Neto

    Thanks, it worked like a charm on my Dell Latitude 3540 using ubuntu 12.04.4 !

  • Uğur Aşkın

    Thank you. Works hp probook 430 g1

  • rainkin

    very thanks! it works in acer 4750g

  • nick sat

    this is not work for my

    Linux lenovo-Ideapad-Z570 3.11.0-19-generic #33~precise1-Ubuntu SMP Wed Mar 12 21:16:27 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux


    Ubuntu 12.04.4 LTS

    i have also nvdia gpu… I have the recommended drivers but a am not sure tha it works properly…

    • may be installing hardware driver may fix for such graphics drivers?

  • Thank you man! Works like a charm after doing this method and a reboot for my Packard Bell Easynote!

  • Aqeel Shoukat

    Its not Working on my HP pavillion DV6.
    I hv installed ubuntu12.04 along with windows 8.
    after making chnges given above when i try the UPDATE-GRUB command it gives me a bunch of errors saying that: cannot seek ‘/dev/sda’

    do you have any Idea about this scenario…???

    another thing ..
    Am I supposed to change the word “vendor” with HP or ACCER??? or it should remain vendor..???

    • Can you try ubuntuforums/askubuntu for the solution? Never experienced the problem

      • Aqeel Shoukat

        It get solved automatically…

  • sigidhanafi

    It work with Lenovo g480

  • Karan

    works on dell 5520. Dual booting windows 8.1 and ubuntu 14

  • slewman

    +1 for lenovo g480. thanks guy!

  • fjreiu9
  • Shiyason

    Initially I found another blog post but they omitted the *sudo update-grub* command. THANK YOU SO MUCH

  • anjali

    Thankyou you saved my eyes…

  • atanu nath

    Did all these and rebooted.. it doesn’t work for me ! And I should mention that this problem wasn’t there initially on my asusx552c

  • atanu nath

    It didn’t work on my asus but then I found this:

    Instead of “quiet splash acpi_backlight=vendor” if I put this “acpi_osi=” it works perfectly.

    Found the solution here: http://ubuntuforums.org/showthread.php?t=2105831

  • Thanks! Work with openSuSE 13.2 in HP Envy 15 k212la

  • A-Star Computing

    adding acpi_osi=” fixed the issue with an Acer Aspire 5734Z with Intel GMA 4500M graphics, thanks for sharing

  • Ibragim Šabanovič

    its not worked for my asus u82u with radeon hd 6320