Lenovo e531 - Fn keys don't work properly

Question

Although Fn + F1, F2 or F3 work well (they stand for audio volume), Fn + F5 or F6 don't. They should make the brightness of a display more and less, but instead they just make the brightness 0 and 10 of 100 and nothing else.

Has anybody faced with the same problem? Have you solved it?

By the way, they work properly in Window, at least at Windows 8.

Answer 1

I got the same problem under 12.04.3 amd64.

I found a post with a similar problem: 12.04 - How to control Brightness

There is a workaround described :

1. Login as root (or use sudo vim) and open "/etc/default/grub"

2. Change the line (line# 11 or near)

   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
   

   to

   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
   

3. Save and close

4. Execute grub-update

5. Reboot

With this the keys work properly but only the brightness bar has still the wrong behaviour.

Answer 2

I can confirm the Fn keys is working on my 14.04.1 thus, by upgrading from 13.04 through 13.10 to 14.04.1 and applying the HWE, your Fn keys will work.

ubuntu@ubuntu:~$ uname -a
Linux ubuntu 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:43:14 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux