[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.

77 thoughts on “[SOLVED] Brightness problem in Ubuntu 12.04 Precise Pangolin”

  1. Hi
    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.

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

    1. 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.

    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

  4. 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”?

  5. After sudo update-grub, I get
    “/usr/sbin/grub-mkconfig: 11: /etc/default/grub: splash: not found”
    Any thoughts?

    1. 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.

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

  7. 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!

  8. 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.

    1. 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.

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

    1. Hi, that shouldn’t have happened. because if you got really really stuck, it should have a prompt called “grub>” rather the error.
      I hate to tell the error description but kindly read the error description here: http://askubuntu.com/questions/176778/12-04-crashes-and-get-i-o-error-dev-sda-sector-xxx-in-console-mode
      Please insert a new USB stick and try to fix up the Grub. may be here (https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows)

    2. This worked for me today (04-Apr-2014) on a Dell Inspiron 15 3521 in Linux Mint 16 (Petra). There was no problem on reboot.

  10. 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.

      1. 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.

          1. 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”

  11. 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!

  12. 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…

  13. 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..???

  14. 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

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

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