This article was originally written for an older version of Ubuntu but it should still be applicable to newer Ubuntu versions and the distributions based on Ubuntu. Let’s first find out what graphics/video card to do you have. The solution, that worked for me, is for Intel one. One relates to Nvidia graphics card and other relates to Intel graphics card. Pressing Fn+A to activate or deactivate the ambient light sensor also does not.
I can see in Windows the brightness control dialog increasing or decreasing when I press Fn+F6 or F5, but the screen brightness either does not change or changes after a long delay (more than 1 minute).
It turns out, there are two bugs related to brightness issue in Ubuntu. Asus Zenbook UX430UN brightness control not working in Windows 10. Brightness was at the maximum and my attempts to lower it went in vain. On my Dell Inspiron, using the function key to change the brightness did not yield any results. In this quick post, we’ll see how to fix brightness function key not working in Ubuntu. If you have issues with the display settings for your system, you can try to modify a registry. When the Windows brightness is not changing, check the power options settings. We saw how to fix no sound issue and no network issue in Ubuntu in other posts. Adjusting the brightness of your computer is not working in Windows 10 if there is an issue with the display driver. Some of the most prominent issues with Ubuntu are brightness control, wifi and sound.
