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Recently i installed Ubuntu 12.04 on my Laptop "Dell Inspiron-N4010".

i am facing problem with my contrast control,after restarting my system contrast is getting reset to its max value.

so each time after login have to set the contrast again & again.

Please advice ....

Regards, Shiv Rajawat

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I got this working on my machine, but as soon as the greeter screen appears the brightness jumps right back to maximum, any other steps I could take to find out whats causing this and override it to make the lower setting stick?

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I faced the same problem on my Dell XPS. Currently there is no other way to save it according to brightness key.

  • Find your brightness control path, execute

    ls /sys/class/backlight/*/brightness

    the output will be something like /sys/class/backlight/acpi_video0/brightness

  • Copy that path and try executing

    sudo su -c 'echo 5 > THE_PATH_FROM_FIRST_COMMAND'

it will be like -> sudo su -c 'echo 5 > /sys/class/backlight/acpi_video0/brightness'

If it succed,try with different value for 5 and choose your preference level.

  • Now edit /etc/rc.local file to execute this command at boot up.

    gksu gedit /etc/rc.local
  • Just before exit in the file, add the following line,


You can change value 5 to anything.

Linked Question:

How do I prevent Ubuntu from changing my laptop screen brightness level?

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Let us know if it worked. – Web-E May 10 '12 at 13:40
Hi Web E, as you told i run the command but i am getting two paths,please see thethakur@thethakur-Inspiron-N4010:~$ ls /sys/class/backlight/*/brightness /sys/class/backlight/dell_backlight/brightness /sys/class/backlight/intel_backlight/brightness thethakur@thethakur-Inspiron-N4010:~$ should follow the same above steps or step will be change in my case... – The Thakur May 10 '12 at 14:33
any one.. I have the same problem. I use first one – Web-E May 10 '12 at 16:03

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