Linux Mint Forums

Samsung r480 laptop.
Linux Mint 13 KDE

The Fn keys for the brightness do not work. I am using this workaround:
sudo setpci -s 00:02.0 F4.b=XX.
The XX is the level of brightness; 0 being the darkest, 100 brightest. I normally have it at 25. If I reboot or sleep the laptop, it will go to a default level, not sure what the number is but its very bright and hurts my eyes after just a little bit.

How do I get the Fn keys to work or at least how do I get the value to stay at 25 by default??

I've been using Mint w/kde on this laptop since Mint 10 and have always had to do this workaround for the brightness.

Thanks.

http://forums.linuxmint.com/viewtopic.php?f=90&t=104540

EDIT: If you had used the forum search for "brightness", you would probably have seen the above link. So try searching the forum, chances are someone has already encountered your problem.

thanks for the reply. yes I have seen this post already which I've done and it worked. thanks. I am still trying to figure out how to control the brightness with the fn keys which, through my search on this site, I have not found a solution.

As far as I am aware, the fn keys won't work for brightness. Also rebooting or putting the laptop to sleep kills the session, and that's why the brightness returns to default. There is no fix for this problem, as far as I am aware.

Hi,
echo -n 100 > /proc/acpi/video/VGA/LCD/brightness

This will make you LCD screen as bright as possible and you can proceed with your work (like me ). To lower brightness just replace 100 with another value like 62 and watch the results.

Hope it helps!
Thanks

Hi,

I have had an Acer Aspire One D270 for a while running Fedora but could only get the brightness keys working by editing the grub file.

but after looking around for ages found the following thread

http://ubuntuforums.org/showthread.php?t=2003100

and so thought I would give Mint 13 XFCE a go and downloaded the cedar drivers and hey presto the brightness key started working.

$ sudo aptitude install cedarview-graphics-drivers

try the above and the brightness Fn keys should start working but it may jump up/dwn in large increments. Oh well thats for another day, i'm just happy to get the keys working

I'm having the same problem with my Acer Aspire 7736z (it's old, I know) and Mint 14 (Cinnamon 1.6.7) (64-bit).

I tried the solution nilan suggested, but each time, the package cannot be located. I did an update before trying to install, and tried aptitude and apt-get just in case.

nilan wrote: $ sudo aptitude install cedarview-graphics-drivers

I was able do find a deb file on Ubuntu's website, but I get an error with that:

Error: Dependency is not satisfiable: cedarview-drm

One thing that I've noticed that I hope may be of some help to finding a more universal solution is that during boot - and specifically while the BIOS is loading, or when the GRUB is displayed - the hardware keys for brightness work! They work perfectly, but then at some point after the GUI loads, this functionality disappears!

I hope that little clue will help some one smarter than I figure this out, or maybe some one could help me get the cedarview drivers installed.

Mint 13 newbie here. Wish to thank everyone for solving the screen brightness issue using "sudo setpci -s 00:02.0 F4.b=XX" for me. I just CTRL + ALT + T to open a terminal and run this line depending on what I am doing.

I run Mint 13 (tried 14 but saw no need to change) on an Acer Aspire 7735Z laptop connected to a second monitor on occasion. Native res on laptop is 1600 x 900 while the external monitor is 1920 x 1080.

The above command is the only thing that has worked. I tried the following which did not work.

a) Cinnamon Brightness applet
b) Editing the ACPI line in Grub
c) echo -n 100 > /proc/acpi/video/VGA/LCD/brightness (result says "no such file")

Thank you everyone.

hi guys
I am using a Linux mint 14 cinnamon 32 bit edition
I am using a HP dv6-6155tx with amd ati radeon 6490 chipset

I have tried all the above mentioned things
This command " sudo setpci -s 00:02.0 F4.b=XX " which is working for everyone does not work for me

What am i supposed to do??
Should i report this as a bug??