After upgrading the Samsung NC110 netbook to Ubuntu 13.04, the screen brightness buttons stopped working. Googling the terms “ubuntu 13.04 samsung nc110 brightness” led to an askubuntu.com thread with the solution.
Here are the steps.
Backup the grub config file
sudo cp /etc/default/grub /etc/default/grub.bkup
Edit the file
sudo vim /etc/default/grub
add the following to the line
GRUB_CMDLINE_LINUX=".... acpiosi=Linux acpi_backlight=vendor"
The ellipsis (….) refers to what was already there and is not meant to be entered literally into the file.
sudo grub-mkconfig -o /boot/grub/grub.cfg