On Mon, Sep 17, 2012 at 10:21 PM, Genes MailLists <lists@xxxxxxxxxxxx> wrote: > > > unplugging a/c and going to battery - laptop beeps - but screen no > longer dims - > > Again - I can dim screen by hand by doing something like this: > > echo '11' > /sys/class/backlight/acpi_video0/brightness > > This has been flaky a while but usually worked at least some of the time > - now its just not working period. > Good tip, didn't knew about it. In my particular case I need to add acpi_backlight=vendor to the kernel line in order to be able to control screen bright with the fn+function keys combination (only in KDE SC, this don't work in dwm or Awesome), may be you can try this to solve your problem.
