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Recently I've installed Ubuntu 10.10 32-bit on my Dell Inspiron i14r-2265, but it looks like brightness control is not working. I can change it "programmatically" (FN + brightness key), though actual screen brightness shows no effect.

I've tried this advice but it didn't work for me.

I actually have no idea how it works (if hardware is not responsive to software, the way I see it), so can someone suggest a solution please?

EDIT:resolved in 11.*

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up vote 2 down vote accepted

I've got the same problem with Ubuntu 10.10 on my Gateway T-6836. The fn + brightness keys work, but the screen always stays at max brightness (or whatever brightness I set at the grub menu). In addition, dmesg provides the following output: "ACPI: Failed to switch the brightness."

The two quick-fixes I've found:

1.) You should be able to adjust the screen brightness with the brightness keys at the grub menu before you load the linux kernel, although this isn't always practical.

2.) Try installing xcalib. You can run xcalib -co 60 -a (where 60 can be any percent) to dim the screen and xcalib -c to clear the settings and restore brightness. You could also map these commands to keyboard shortcuts, essentially rigging up two new brightness keys.

Granted, these don't address the real problem, but they were the only solutions that worked for me. Hope this helps.

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I have same problem with my Dell studio laptop. What is did was i set the multimedia key first then function( key from bios.

Means set the bios such that to increase the brightness you have to press the multi-media key and to press F<1-9> you have to press Function-key+multimedia key..

Check if this is working and revert back...

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Programmatically brightness is changed, but nothing actually happening with the display. – Denys S. Feb 15 '11 at 18:58
sorry for delayed reply. Did you tried to adjust the brightness from power control. System->preferences->powercontrol. – Abhijeet Feb 24 '11 at 15:06

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