LCD brightness keys not working in Kubuntu Gutsy : Computer and Technology | Ubuntu Linux

LCD brightness keys not working in Kubuntu Gutsy

I recently upgraded one of my laptops from Kubuntu Feisty to Kubuntu Gutsy and all seems to work well except for the LCD brightness keys. For some reason, ACPI is not working properly when it comes to handling the brightness keys on my laptop. A quick search at Google led me to this bug report (Bug #145337) and it looks like that I’m not the only one suffering from this.

Upon reading the bug report, I decided to do some testing of my own and found a temporary workaround – temporary because I hope that the Kubuntu/KDE people would have this fixed on their next update. I posted my workaround in the bug report and am also including the quick fix here.

Disclaimer: While I did write the script below and it does work on my laptop (Gateway ML6720), I make no guarantees that it will work on yours nor will I provide support of any kind except through the comments section of this particular blog post. Furthermore, I bear no responsibility should this script cause any harm to your computer.

Download lcdbryt.sh LCD brightness workaround for Kubuntu Gutsy

Instructions:

sudo cp lcdbryt.sh /usr/bin
sudo chmod +x /usr/bin/lcdbryt.sh
sudo pico /etc/acpi/video_brightnessup.sh
1. add the following line at the end of the file
  lcdbryt.sh up
2. save (Ctrl+X then Y)
sudo pico /etc/acpi/video_brightnessdown.sh
1. add the following line at the end of the file
  lcdbryt.sh dn
2. save (Ctrl+X then Y)

Test your brightness keys again and perhaps it will work this time. Hope this quick fix for the LCD brightness keys not working in Kubuntu Gutsy helps you.

October 27, 2007 · Posted in Technology

Comments

26 Responses to “LCD brightness keys not working in Kubuntu Gutsy”

adrin on December 26th, 2007 2:07 am

did not work on dell inspiron 6400
sandro on January 16th, 2008 10:19 am

Works on my HP Compaq dv6210br. Thanks!
Junior on January 21st, 2008 8:01 pm

Will this work on Ubuntu as well, or only for kubuntu?
Junior on January 21st, 2008 8:05 pm

Well, it din’t… I’m on a hp dv2130 and using Ubuntu
Junior on January 21st, 2008 8:50 pm

WAOOOO, I LOVE YOU! It worked! I know many people haveing issues with this! Ignore my last post, I just wrote something wrong in terminal
rufensis on January 23rd, 2008 12:31 am

Worked like a charm on an HP dv2000. Thanks, Mike.
Kevin Funk on January 24th, 2008 2:30 am

Works perfektly on a Dell XPS M1530. I had to replace “VGA” with “VID” in the script. Maybe “/proc/acpi/video/VGA” is deprecated?
Max on January 29th, 2008 11:36 am

As Kevin said on his post, I had to replace “VGA” with “VID” in the script. Worked like a charm after that.
arild on February 9th, 2008 11:37 am

Works 100% on a HP G6000 series laptop as well (G6065EA to be precise).

Had to change the VGA directory referenced in the script to UVGA, otherwise fine.
Weeber on March 28th, 2008 11:09 pm

Worked like a charm on a HP pavilion dv2423la using ubuntu gutsy. Thanks dude!
NrgJack on May 16th, 2008 11:44 pm

Thanks man,
it works perfectly on my “hp dv2172ea” under ubuntu hardy heron.
LeGrec on June 27th, 2008 4:46 pm

Thanks!
Works perfectly on hp Presario V6355EU under kubuntu 8.04 KDE 4.1
Leonardo Olmos on July 4th, 2008 2:18 pm

Thanks, Works perfectly on COMPAQ PRESARIO V3218LA unde UBUNTU hardy.
ben on July 18th, 2008 5:30 am

Great, brightness bug fix works perfectly on Compaq Presario V3000 Kubuntu 8.04
avgeneral on July 21st, 2008 12:56 am

it works but how come it does not affect the battery life?
Mike Lopez on July 21st, 2008 5:39 am

Hi avgeneral,

In my case it does affect battery life. I get an extra 30 to 45 minutes at times.

Mike
Dipti K on August 6th, 2008 10:33 pm

Hi all!
I’m a new convert from Windows and am using Ubuntu 8.04. I too use a HP-Compaq Presario V3000. I need some help in executing the directions mentioned above. I have downloaded the required file. What next?
-lost
Mike Lopez on August 6th, 2008 11:14 pm

Hi Dipti,

You execute the commands above one line at a time in the console/terminal. The terminal is akin to the Windows “DOS/Command Prompt”.

Mike
Anzu on August 12th, 2008 3:16 pm

works on pavilion dv6768se
nicholas fellows on August 25th, 2008 7:42 pm

nailed … confirmed working on a Compaq Presario C700 running regular ubuntu (hardy heron)
Dan on September 30th, 2008 7:49 am

Works on Gateway MT6821 running Ubuntu 8.04 LTS
tamalatamala on October 11th, 2008 7:57 pm

Doesn’t work for me. HP Compaq 6735b, AMD, on Kubuntu 8.04 Hardy
DV on October 19th, 2008 7:37 am

great, works perfect on Gateway MX6447 using ubuntu 8.04!
Maged on February 13th, 2009 5:00 am

Doesn’t work for me.
I’m on HP 6730s and Ubuntu 8.10
Sava on April 30th, 2009 10:04 am

For those of you who hasn’t got this working:

Make sure the path

/proc/acpi/video/VID/LCD/brightness

is correct on your system. For example, the instruction reads:

/proc/acpi/video/VGA/LCD/brightness

while my Ubuntu/DellXPS has:

/proc/acpi/video/VID/LCD/brightness (note VGA vs VID)

Simply open Terminal, and then cd /proc/acpi/video/ then tab for it to display what’s in there, and go with it.

You’ll also need to edit the lcdbryt.sh file, the last line

echo -n $current > /proc/acpi/video/VGA/LCD/brightness

to match that path as well. After that it should work flawlessly.

Thanks alot Mike,
hpd1000member on August 18th, 2009 3:14 am

how does it work?