My Samsung laptop (series 7 Chronos, Radeon graphics, Core i5) came originally with Windows 8. When upgraded to Windows 10 the display brightness became stuck at maximum. The function keys also became unresponsive. But that is a different story.

After a lot of complaining and dely, Samsung provided a stand alone software that adjusted the brightness. It was not integrated into Windows 10. I got tired of the whole things and ditched Windows 10 and started using Ubuntu. Now I am still stuck with this dazzling bright screen which does not respond to brightness controls provided by Ubuntu.

I noticed that many people have had the same problem with other types of computers. I have tried some of them, but so far to no avail. Being new to Ubuntu I don't want to try anything too drastic in case I mess up my Ubuntu set up which is working very well at the moment.

I would be grateful for any suggestions that can fix the problem (and save my eyesight!)

Many thaks in advance


I found a bug report on launch pad describing the same problem and some solutions: Samsung 7 screen brightness

Basically ACPI is implemented improperly on your motherboard with Intel CPU and Radeon graphics. The solution is to add the parameters acpi_osi=linux and acpi_backlight=video to your kernel command lines in Grub. You can google how to modify grub kernel parameters and ask any questions you have on updating grub.

  • A solution offered at: lordamit.github.io/Brightness has partially worked for me. I say partially because the python app, when executed, disables the terminal window and I have to open a new one. But it is better than nothing. I will try the suggestion by WinEunuuchs2Unix as soon as I know how to modify grub kernel parameters. – elmclose Aug 31 '16 at 6:50
  • It's described in AskUbuntu: how-do-i-add-a-kernel-boot-parameter – WinEunuuchs2Unix Aug 31 '16 at 10:13
  • Success! I added the parameters to the kernel command line in Grub as suggested above and rebooted. Brightness control was back. Thank you WinEunuuchs2Unix, you saved my laptop (and eyesight!) – elmclose Aug 31 '16 at 13:18
  • I understand the eyesight point. I had same experience in 2014 when I started Ubuntu with my old Toshiba laptop. Could you upvote answer back to zero and mark as solved please. Thanks – WinEunuuchs2Unix Aug 31 '16 at 14:57

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