Now I Know That Technical Thing Too

I installed Linux Mint Qiana 17.2 on my (very old) Acer Aspire laptop. Was pretty surprised that I was not able to adjust the screen brightness using the laptop buttons. The hack I got was as follows, Open terminal (as a superuser) We now need gksudo to edit the grub file You can do gksudo gedit /etc/default/grub   In the text file that opens, look for the line which says GRUB_CMDLINE_LINUX="" In the empty quotes i.e. the "" insert the words "acpi_backlight=vendor" The line now looks like this GRUB_CMDLINE_LINUX="acpi_backlight=vendor" Remember to save before you close the file Back again in the terminal session, type sudo update-grub Reboot ACPI is Advanced Configuration and Power Interface It is used when the machine starts to control the amount of power given to each device attached to the computer. When we do acpi_backlight=vendor it tries to load vendor drivers before it tries the default generic driver for screen