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I am unable to change the brightness of my Acer Aspire V3-571-6850 laptop.

My system details are:

Memory: 7.6 GiB Processor: Intel Core i5-3210M CPU @ 2.50Ghz * 4 Graphics: Intel Ivybridge Mobile OS type: 64-bit Disk: 730.0GB

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please provide system details, in particular the graphics card you are using, and whether you have installed the graphics drivers. – amc Jun 24 '13 at 4:43
I have not installed any drivers – TheProgrammer Jun 24 '13 at 4:54
please open a terminal (ctrl+alt+t) and post the output of lspci | grep VGA. – amc Jun 24 '13 at 14:06
here is the output: – TheProgrammer Jun 24 '13 at 16:38

You can change brightness using command line as follows:

  • Open Terminal (Ctrl+Alt+T) and type

    $ ls /sys/class/backlight/
  • You will get some output like intel_backlight sony. If you have intel_backlight as one of the outputs, it means that you have Intel Graphic driver installed.
  • To know the maximum brightness supported by your screen, type

    $ cat /sys/class/backlight/intel_backlight/max_brightness

    Here, intel_backlight can be replaced by your graphic driver folder name.

  • To change the brightness to your desired level, type

    $ echo 3000 | sudo tee /sys/class/backlight/intel_backlight/brightness

    where 3000 can be replaced by your desired brightness level, upto your maximum screen brightness number.

For more information, refer to this backlight Wiki.

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You may need to install proprietary drivers for your graphics card.

  1. Go to the gear icon in the top right corner of your screen and select "System Settings..."
  2. Select "Software & Updates"
  3. On the "Additional Drivers" tab, select a proprietary graphics driver (I suggest starting with the *-updates one, with the highest driver number, as it tends to be the most recent and up to date. For example, see image below for my nvidia card.)
  4. Once it's installed you will need to reboot your computer for the settings to take effect.

enter image description here

[EDIT: additional information on Intel Graphics]

Intel graphics drivers for Ubuntu 13.04 have recently been packaged and released by Intel in an Ubuntu installer:

  1. Download the appropriate .deb file for your system architecture (32 bit or 64 bit)
  2. Get the intel repository key so the packages will be trusted:

    wget --no-check-certificate -O - | \

    sudo apt-key add -

    wget --no-check-certificate -O - | \

    sudo apt-key add -

  3. Install the package (.deb) you downloaded by opening it in Software Centre

I can't vouch for how well they work, since I don't have an Intel graphics card, so just be sure you follow the instructions and be aware of any "Known Issues" that are presented on the package website.

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but this is what shows up when i click on 'additional drivers' in the third step. – TheProgrammer Jun 24 '13 at 6:21
I see you added more info to your question and that your using intel graphics. I'll post more in the comments to your original question. – amc Jun 24 '13 at 14:01
@fidgetyphi updated answer for intel graphics – amc Jun 26 '13 at 4:09
and this is the 'failure message' that I get when I try to install the driver with the above mentioned 'Intel Driver Manager' software: – TheProgrammer Jun 26 '13 at 22:22
that's a 404 error which means you weren't connected to internet when installing or their server was down. I suggest trying again. Hopefully it was just a temporary glitch. – amc Jun 28 '13 at 0:55

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