Hello
I have strange problem.
My laptop is Dell Studio 1537. I use kubuntu 64bit last version.
When kubuntu loaded my Fn + up/down arrow for brightness working, but I login this functions not working.

my brother have same laptop Dell 1537 but he install 32 bit kubuntu and KDE 3,4. everything is working.

Different between both laptops is my laptop have 4GB RAM and 9 cell battery and lightens keyboard, other dell have 3GB RAM and 6 cell battery.

Same problem width this up/down brightness (Fn + up/down arrow) when I install ubuntu 64bit. http://ubuntuforums.org/showthread.php?t=1187617

Other test: delete everything install 32 bit kubuntu. Then I have same problem with brightness.

how resolve this problem.

thanks for help

Moved to Linux forum.

Can you check to see if the system registers that these keys function? This can usually be done with the "xev" utility in Konsole. It should output something similar when you press the brightness keys. Note that you should not press any other keys or move the mouse since they will also cause output to be generated.

Code: Select all

KeyPress event, serial 34, synthetic NO, window 0x3600001,
    root 0x7e, subw 0x0, time 33592995, (140,208), root:(144,233),
    state 0x0, keycode 212 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:                                   
    XmbLookupString gives 0 bytes:                                 
    XFilterEvent returns: False                                   

KeyRelease event, serial 34, synthetic NO, window 0x3600001,
    root 0x7e, subw 0x0, time 33592995, (140,208), root:(144,233),
    state 0x0, keycode 212 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:                                   
    XFilterEvent returns: False

when I run "xev" in my konsole

Code: Select all

KeyRelease event, serial 31, synthetic NO, window 0x3600001,
    root 0x9d, subw 0x0, time 42852623, (396,762), root:(399,791),
    state 0x0, keycode 233 (keysym 0x1008ff02, XF86MonBrightnessUp), same_screen YES,                                                                         
    XLookupString gives 0 bytes:                                               
    XFilterEvent returns: False                                               

KeyPress event, serial 34, synthetic NO, window 0x3600001,
    root 0x9d, subw 0x0, time 42856168, (396,762), root:(399,791),
    state 0x0, keycode 232 (keysym 0x1008ff03, XF86MonBrightnessDown), same_screen YES,                                                                       
    XLookupString gives 0 bytes:                                               
    XmbLookupString gives 0 bytes:                                             
    XFilterEvent returns: False


Every key event registered but not change brightness.
may be power menagement or something else is defected.

Strange problem is my brother laptop everiting is default. Run CD install kubuntu this Fn + up/down arrow is working every moment when pressed.

Don't run as root.

It appears there must be some differences between your machines. Perhaps one of the machines has a different BIOS revision? Screen brightness is usually altered at the kernel level.

To confirm this, open Konsole and run the following:

Code: Select all

cd /sys/devices/virtual/backlight/acpi_video0
cat max_brightness
cat actual_brightness
sudo echo '5' > actual_brightness

The brightness should change for the final step. If nothing changes then a Kernel level issue is preventing them from functioning.

cd /sys/devices/virtual/backlight/acpi_video0

this folder backlight not exist in my laptop.

but other laptop with working brightness functionaly also backlight folder not exist.

I install xbacklight http://www.lesswatts.org/tips/graphics.php run this xbacklight -set 50 nothing change. Mаybe something not install in my 64bit kubuntu. I download from http://www.kubuntu.org/ mаybe something missing in instalation CD. Mаybe kubuntu 64bit conflicted width new bios version (Studio 1537 System BIOS A09) in dell

my BIOS version is A09 from dell.com. Before 1 month ago my windows vista show blue screen. I update bios version, then change my OS width kubuntu.

Hmm. interesting.

Can you post the results of the following command here?

Code: Select all

sudo find /sys /proc | grep brightness

Code: Select all

/sys/module/video/parameters/brightness_switch_enabled
/proc/acpi/video/M86/HDTV/brightness
/proc/acpi/video/M86/LCD/brightness
/proc/acpi/video/M86/CRT/brightness


edit:

I`m very hapy. this functionality Fn + up/down brightness now working.
Before post I install xbacklight (apt-get install xbacklight) but not restart. Before 1 hour ago my pc is shut down. Now I make test width Fn + up arrow and down arrow this is working.

Thanks for help me.

I have other problem width Fn + up/down arrow brightness.

Turn power on my pc. Boot from kubuntu. login, set password KDE Wallet, start skype, Firefox or other programe after few minute change brightness width Fn + up/down arrow stop working.

can i fix this problem.

Can you try and trace the exact program that is preventing the brightness from being changed? This could be done by testing to see which application causes the controls to stop working. You may also wish to check the battery applet, and see if its brightness controls function when the keys stop working.

my step to stop brightness
1. login (working)
2. start Firefox (open 2 tab wokring brightness)
3. File Menager (continue working)
4. start and login skype (working)
4. Start vlc player watch movie (avi files) continue working and close vlc player
5. start mozila thunderbird read 2 emails (working)
6. open new tab in firefox url address with flash movie (swf) http://vbox7.com/play:5faea1c8
then brightness stop working.
my flash plaeyr is (apt-get install flashplugin-nonfree)

other test
restart my pc wait 3-4 minute before input username and password. input password KDE Wallet, skype program automatic start ask me input password to login, then brightness not working.


my power menagement screen brightness http://nds-bg.org/pictures/power_menagement.png never moved when I change brightness with Fn + up/down arrows. I edited profile to minumum, because my screen is
very bright. I aлways use minimum brightness in my screen, sometime when I watch movie or other darken screen I want up brightnes in my screen.

Flash has been known to steal keyboard input. If you close the offending web page, does brightness control return to normal?

When stop working, brightness control return to normal when restart my pc.

I can tell you exactly what causes this issue under Linux on this machine, it's the ACPI specification that is laid out within the A09 BIOS. If you check your system log you should see ACPI begin to puke at the exact time your brightness controls stop working.

The most common error message that I have found is "ACPI: EC: Input buffer not empty, aborting".

You'll need to download BIOS A07 or A08 (I recommend A07) which is in an EXE format, execute it as an administrator under an installed Windows environment, then return to Linux and all should be well.

Please ensure that you have installed the latest updated Kernel available, as it may contain fixes for the issue.