Solve the problem that Ubuntu14.04 cannot adjust the screen brightness.

Solve the problem that Ubuntu14.04 cannot adjust the screen brightness.
After Ubuntu 14.04 is installed, the "system settings" option is the most preferred one, because you want to adjust it to your favorite style first (of course, if you want to adjust it further, you need to use other software), and then slowly modify it. The screen brightness of Ubuntu is the largest by default, and it looks very dazzling, so I want to reduce it a little, but no matter how it is adjusted, so I didn't care about it for the time being, I forgot about it. Today, I just got free, so I simply went to find a solution. It seems that everyone has encountered this problem, so there are many solutions. Below I will write a solution that I personally think is relatively simple:

Terminal input code:

1	Sudo gedit/etc/default/grub

Find

GRUB_CMDLINE_LINUX = ""

Change

GRUB_CMDLINE_LINUX = "acpi_backlight = vendor"

Save the changes.

Then, upgrade grub:

1	Sudo update-grub

Restart... You can adjust the value by FN.

Used to set the initial brightness value:

Terminal input code:

Sudo gedit/etc/rc. local

Add a sentence to open the file (before exit 0)

Code:

Echo 500>/sys/class/backlight/intel_backlight/brightness

Save it.

After the above method, you can adjust the screen brightness, and the brightness value you set will not be changed after restart.