Unusably dim screen in KDE

[Linuxguy123]

On Tue, 2011-04-05 at 21:11 -0500, Ian Pilcher wrote:
> Fedora 14 (x86_64) on a Lenovo ThinkPad T510 an "nVidia Corporation
> GT218 [NVS 3100M]" GPU.
> 
> I normally don't use my laptop's built-in display when it's at
> home, so I'm not exactly sure when it started, but I suspect that
> the recent update to KDE 4.6 was probably the trigger.
> 
> I can boot my system and log in to GNOME just fine.  Logging in to
> KDE, however, causes the brightness of my laptop display to become
> unusably dim.  This happens whether or not the laptop is running on
> AC power.  The screen does return to its normal brightness momentarily
> when I connect AC power, but it then returns to its dim state.
> 
> The KDE brightness controls are still set to full brightness; I can use
> them to change the display from unusable dim to completely black and
> back.
> 
> The only way I have found to restore the display to its normal
> brightness (until I log in to KDE) is to reboot.
> 
> Anyone have any idea what might be going on?  I really am completely
> unable to use KDE this way.  :-(


I bet it has something to do with your power settings.

Kstart->Settings-> System Settings -> Power Management-> Power Profiles
-> Display Brightness.