Fix your laptops brightness function keys operating properly in Hardy

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If you recently installed Ubuntu Hardy Heron 8.04 and discovered that your laptops function keys are not properly adjusting the brightness. In essence, you are pressing the key combination and nothing is happening try this fix.

Before doing any changes you need to take backup of existing files

Now you need to download the following files in /etc/acpi/ directory

Download from here

Download from here

After replacing these scripts

No reboot or logout required, simply press your function combination on your laptop to change brightness. Try to press FN + Up/Down Arrow.

Credit goes to AaronMT

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37 Responses

  1. Angelo says:

    Actually, I don’t have any problems with my function keys on my DeLL Inspiron 1420.
    All keys were functional from the moment I’ve installed Hardy.

  2. João says:

    hello, i have a SONY vaio VGN-FZ21E and to adjust the brightness i use the keys Fn + F5 (less brightness) and Fn + F6 (more brightness) but in Ubuntu Hardy Heron i can’t adjust the brightness and this fix do not result in my laptop, can you help?

  3. borworn says:

    My Fujitsu Lifebook has problem with brightness function keys and this fix also does not fix the problem. The function keys work correctly in Windows.

  4. PivuSan says:

    Hello João! Tell me please. The Web-camera works for you?

  5. Greg says:

    I just wrote a tool in C to do this same task. DOH!

  6. admin says:


    Is it possible to share with us or you can submit as article to ubuntugeek


  7. Helman says:

    For those of you who had tried this tip but didn’t work, let me share my experience (on HP Compaq Presario V3000).

    First, type this command:

    >> cat /proc/acpi/video/VGA/LCD/brightness

    which will show on the screen something like this:

    levels: 100 60 20 28 36 44 52 60 68 76 84 93 100
    current: 100

    Then change the brightness values in and to match the values shown after the word ‘levels’ above.

    Also, don’t forget to set the file permissions of and so that they become executable.

    Hope this works for you too!

  8. Treval says:


    I have the same problem on my Fujitsu Amilo 2515 laptop. It looks to me as though the video_brightnessup & down scripts are not being called at all.

    Anyway, as a quick workaround use the following script from a terminal window:



    if [ $# = 0 ]

    echo ${bval} > /proc/acpi/video/GFX0/DD02/brightness


    On my machine, valid values for brightness are: 13, 25, 38, 50, 63, 75, 88 , 100

    If you invoke the script without a value, the brightness will be set to 75% which I find adequate for most environments.

  9. Max Magliana says:

    The script needs to be edited depending on the notebook being used. Not all monitors accept the same values for brightness. Mine are:

    95 43 20 24 28 32 37 43 50 59 69 81 95

    Also, most people will probably not know that they have to make the scripts executable with:

    sudo chmod a+x /etc/acpi/video_bright*

    Otherwise it will definitely not work.

  10. dave says:

    hello everybody,

    i have these function-keys problem, too. what i tried out is the follwing:

    – edited the and files
    – filled with the values from /proc/acpi/video/NVID/LCD/brightness
    – set the attributes to execute

    then i tested the settings, and it stilld doesn’t work.
    i found out that, when i am pressing the function-keys it affects the brighness-file (checked the current-value)

    but the display is at maximum brightness and the current-values says: it is at 10! evertime i push the change-buttons the current-value changes, unfortunately not the real brightness of the display.
    using the function-keys in a textconsole (STRG+ALT+F1) works.

    is there any solution to this? or did i forgot anything?

  11. Ian says:

    Hey, I just wanted to thank you for saving my eyes, as I could feel them breaking as I scoured the internet for a fix with an incredibly dim screen. Thanks for the fix (for others wondering if this will work for them, it helped Hardy Heron make the brightness buttons on my HP Pavilion dv6000 work again)

  12. xbacklight-user says:

    What’s the advantage of this script over using xbacklight?

  13. Daniel B says:

    Hey Peoples,

    This fix did not work for me. I am using a Pavilion dv3000 and thought I would give it a good.

    Running it from command line results in the following:

    grep: /proc/acpi/video/VGA/LCD/brightness: No such file or directory 35: cannot create /proc/acpi/video/VGA/LCD/brightness: Directory nonexistent

  14. Ben2K says:

    Anyone got a working solution for this in Karmic Koala, 9.10?

  15. cees says:

    Hi, I have an Acer aspire 4810T and the brightness can not be changed under Karmic Koala. The function keys are working and the numbers under /proc/acpi/video/OVGA/DD02/brightness are changing accordingly.

    But the only thing I see is a bright display.

  16. Ben2K says:

    Update to my earlier comment on Ubuntu 9.10. Using the beta, the brightness controls were DOA, but when I installed all the updates after the final release, the brightness widget suddenly started working on my Vaio Z530N.

  17. chytu says:

    I have a Acer Aspire 4736G laptop with Ubuntu 9.10 (Karmic Koala) installed on it. And I have the same problem as cees above. The FN+ combination shows that the brightness is decreased/increased but the screen remains in same brightness. I can change the brightness using the same combination in my Windows. Please suggest a fix for this problem. Is this a problem with not installing Acer drivers or is it a problem with Ubuntu?

  18. Ben2K says:

    Have you tried the brightness applet on the panel too? (You may have to manually add it.) If that doesn’t work, it probably is a driver problem.

  19. how can i change the settigns of the brightness of my laptop for if plug it in the it darkens, while if i’m only using battery it is real bright..


  20. syarif20 says: using acer aspire 4736 laptop.
    im also having the same problem as you guys.
    My diplay brightness is not functioning.

    My solution is:
    1. Install COmpiz (Advanced Desktop Effect Settings (ccsm) from Add/Remove..

    2. After finished, go to System > Preferences > CompizConfig Settings Manager.

    3. At Accessibility Column, tick the Opacity, Brightness And Saturation and click at the word.

    4. There are Opacity| Brightness | Saturation tab. Choose the brightness tab.

    5. You will see keyboard(increase),mouse(increase),keyboard(decrease),mouse(decrease) icon at the left. At the right of it, you will see Disable button.

    -Brightness Increase-

    6. Click at the disable button of keyboard(increase) and tick the enable box.

    7. Now, put your own combination. Lets say we want to make it as CTRL + right button. There are a choice:

    Shift Super
    Ctrl Alt

    8. Click at the Grab key combination.

    9. ccsm windows will pop up. Press ctrl + right button on your keyboard and press ok..

    10. Now you have done for the Brightness increase button.

    -Brightness Decrease-

    11. Click at the disable button of keyboard(decrease) and tick the enable box.

    12. Now, put your own combination. Lets say we want to make it as CTRL + left button. There are a choice:

    Shift Super
    Ctrl Alt

    13. Click at the Grab key combination.

    14. ccsm windows will pop up. Press ctrl + left button on your keyboard and press ok..

    15. Now you have done for the Brightness decrease button.

    -Try it OUT-

    Now, go to the desktop and press CTRL + left button on your keyboard repeatedly and CTRL + right repeatedly.

    It is working??

    Note: this brightness working at all active windows.

    try open up mozilla and press the CTRL + left button. Mozilla will get dimmer.
    Try open up terminal and do the same things. The terminal will get dimmer to.
    press CTRL + right to get it brighter.

    Happy playing!!!

  21. murali says:

    thanks man. me too own 4736. i installed MINT .. workin great

  22. raj says:

    I have dell new inspiron R 14 with Ubuntu 10.04 installed. I am not able to control brightness. some one please help.
    these solutions here I tried none worked


  23. Ben2K says:

    Are you using the brightness applet on the Gnome panel?

  24. raj says:

    I am not aware of Brightness Applet. How do I enable/use this ?

    I am able to control brightness from grub menu.!!

    Thanks a lot.

  25. Ben2K says:

    Iff you are using Gnome, right-click on the panel you want to add it to, select “Add to Panel”, then drag the Brightness Applet to where you want it on the panel.

  26. raj says:

    I have added the same to panel. But it is saying “Cannot get Laptop Panel Brightness”!

    any clue ?

    Thanks a lot.

  27. raj says:

    I have tried with new kernel installation. The Display of brightness control is coming when I am pressing keyboard button and the applet is also showing up down controls. But the brightness is constant.

    Thanks for any update.

  28. Mario Zaizar says:

    How increase/decrease the brightness in Sony Vaio laptops with Ubuntu 10.10 using Bash.

  29. abl says:

    to adjust brightness on acer aspire, press fn + left arrow key with the sun logo on it, to reduce brightness and the right arrow key to increase brightness.

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