I have recently installed 12.04 on ASUS-K53SV-V300. I can change the brightness on start-up with: echo 0 > /sys/class/backlight/acpi_video0/brightness >> /etc/rc.local or manually by Fn key. But, whenever Ubuntu dim my screen brightness to save power or wake-up from suspend or inactive for 20-30 seconds, brightness reset to high (my problem get much more when on battery). How can I disable screen brightness service to prevent it from changing my brightness? What service work on screen brightness? If I disable this service, can I manually set brightness by command? I found a program to work on brightness instead of default power manager.