I know this is an old question , but the only option option was
to post as a newbie.
I have a Toshiba P850 satellite laptop.
Intel I7e Ivory Bridge
Navida Gforce 630m video card.
was dual booting Win 8 and Ubuntu , now just running Ubuntu 14.04LTS.
The FN keys and LED keyboard were working with either Ubuntu 12.04
Remix or Ubuntu 13.10.When I updated to 14.04 LTS these items ceased
to work. I have tried to edit commands that I found for these issues
but I still haven't been able to solve them .
Any advice or solutions would be greatly appreciated

Hi & Welcome to LQ.

I found some information for you about Ubuntu 12.04, Ubuntu 13.10 and Ubuntu 14.04.
12.04 used kernel 3.2 and 13.10 used kernel 3.11.
http://askubuntu.com/questions/51713...kernel-version

I'm not a Ubuntu expert but I suspect that the kernel (3.13) that Ubuntu 14.04 may not have support for the backlight on the keyboard.

You could try installing kernel 3.11 which worked for you when you were running Ubuntu 13.10 and see if that works with your Ubuntu 14.04.
If not Ubuntu 16.04 is using a higher version of the kernel and I'd think that it would have support for backlighting. Ubuntu 16.04 comes with kernel 4.4.

Try Testing For A Workaround on this page. Maybe it's a bug? <OR> maybe it's a module/driver issue?
https://wiki.ubuntu.com/Kernel/Debugging/Backlight

After reading this it might be the toshibia_acpi driver.
https://techoverflow.net/blog/2014/0...klight-issues/

https://www.linux.com/blog/how-insta...x-mint-systems

Hope that helps.

thank you for quick reply i am in the process of trying the links you suggested

You're Welcome:-

any news update for this working toshiba p850 keyboard backlight?

This might work: https://askubuntu.com/questions/4511...ys-not-working