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I bought a laptop Toshiba Satellite L850-DJS. There was Windows 8 installed at. I installed Kubuntu 12.10. All works perfectly, but i can't change screen brightness. Maybe someone had this problem and helps me.

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directory /sys/class/backlight is empty – Alex_Crack Feb 13 '13 at 7:49
up vote 0 down vote accepted

Here is how I did it the easy way:

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Thank you for response. But it doesn't work, because my directory /sys/class/backlight is empty The main problem is that no devices for changing brightness was found in my system. – Alex_Crack Mar 4 '13 at 8:01
That means you are missing acpi-support on your machine. It is usually installed by default in most distributions, but since it is not there in your case, you can try this: sudo apt-get install acpi-support – Prahlad Yeri Mar 4 '13 at 8:05
There is the last version of acpi-support is installed in my system... – Alex_Crack Mar 4 '13 at 14:31
In that case are you having the 3.4 kernel? It did break some backlight things. You can verify it by typing "uname --a" in a terminal. If yes, then you may either upgrade your kernel, or add acpi_backlight=vendor in menu.lst as given in this link: – Prahlad Yeri Mar 4 '13 at 14:53
My kernel has version: 3.5.0-25-generic – Alex_Crack Mar 5 '13 at 6:21

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