karmic brightness problem again

**jarongg** · November 2nd, 2009

last night, before i installed karmic, i was researching it a bit and found that a bunch of people were having problems with the brightness adjusting itself and generally freaking out. now, as i am experiencing this, i can't seem to find the fix for it. can anybody link me to a thread where this is resolved? thanks.

**ximatz** · November 3rd, 2009

Yup. I must sadly confirm this, as I have been affected too. I have just installed Karmic on my Esprimo Mobile U9200. Before I installed Karmic, I was using Jaunty on my laptop. I found on the web a very usefull site on the Kubuntu wiki, wich had instructions to solve this problem (and may others also): https://wiki.kubuntu.org/LaptopTesti...suEsprimoU9200

All solutions worked fine for me on Jaunty, but they seen to have no effect on Karmic. Bleading edge technology has its price, as too many changes are required...

I am also looking for a solution, but until now: NADA

**ximatz** · November 21st, 2009

Brothers, I am a believer: Trust the community!

I received a message from chessnerd, who kindly shared a working solution for this problem with me. You can find chessnerd's original post here:
http://ubuntuforums.org/showthread.php?t=1331709

A resume of chessnerd's solution, which by the way worked for me:

1) Open Grub2 file.

Code:

  
 sudo gedit /etc/default/grub

2) Add line on Grub2 file.

Code:

  
 GRUB_CMDLINE_LINUX="nomodeset acpi_backlight=vendor"

3) Update Grub2.

Code:

  
 sudo update-grub

4) Reboot your computer.

5) Now brightness should work as expected.

I must admit, I was tempted to try another disto because of not only this problem, but also of other two problems I was having with ad-hoc wireless connections and inverted touch pad two-finger-gestures, which I have more or less resolved by now.

My findings: if it does not work in Ubuntu, it does also not work anywhere else.

I think the problem lies actually on GNOME's brightness manager, which does not allow users to adjust the brightness and sets instead a default value every time the user tries to set the brightness up or down. It is just a feeling...

I hope this helps others further!

**cybil** · November 25th, 2009

Did it make anyone's video sluggish?

**tayran** · November 26th, 2009

I have tried the solution above. I am using Karmic on a MSI Wind re-branded netbook with same hardware. Now brightness is fixed at full. Brightness shortcuts do not work and i don't experience any sluggish video. That is ok for me for now until finding a better solution.

**cybil** · November 27th, 2009

Yeah, my brightness shortcuts don't work either. It is a shame, because they worked previously.

**SirLagz** · February 7th, 2010

I have the issues on my Lenovo laptop as well, and when I disabled power saving the brightness stopped changing itself, however the brightness FN keys do not work.