Arch Linux

mcanes

Member

Registered: 2009-10-09

Posts: 3

Screen backlight turns darker (randomly)

System: dell latitude e6400. intel 4500Hd using xf86-video-intel and kms. kernel 2.6.31-3. KDE.

This problem appeared last Friday and happens randomly when the laptop is running plug or unplug from AC or battery. Screens backlight turns darker than usual (darker using the battery). When this problem happens I can still changing the backlight from the powermanager and the keyboard but darker as before and i need to shutdown and restart to solve the problem (reboot doesn't work). I'm trying to reproduce this problem without using the arch installation (bios, test) but doesn't appear.
("Dell Technical Support say that is a linux problem").

Anyone has any idea?

Thanks!

scio

Member

From: Buffalo, NY

Registered: 2008-08-05

Posts: 366

Re: Screen backlight turns darker (randomly)

In system settings I believe there is a power management section.  One of the options there should be screen brightness changing based on power profile.  Do you have laptop-mode-tools installed as well?

mcanes

Member

Registered: 2009-10-09

Posts: 3

Re: Screen backlight turns darker (randomly)

Sorry for the delay.
Yes, I can change the screen brightness based on power profiles but when this error happens the backlight is always lower than before (on 100% brightness).
I don't have the laptop-mode-tools instaled.