Asus X200MA brightness keys, Googled various blogs and threads, still stuck

[nic_de_vera]

Installed Ubuntu 14, the fn + F5, F6 brightness keys don't work, locked on max brightness. This blog post said add GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_os_name=Linux acpi_osi=" to the grub file, did that, now I can decrease brightness by one click and that's as far as it will go.
GRUB_CMDLINE_LINIUX_DEF

[NoWayWin8]

Does it work if you change it to this: GRUB_CMDLINE_LINUX_DEAULT="quiet splash acpi_backlight=vendor" Remember to run sudo update-grub after editing etc/default/grub or the changes aren't applied.

[vq1]

I have a HP elitebook 2730 and I also tried those grub edits with no success.

Instead I got xbacklight and xbindkeys

and choose the hotkeys I wanted to dim and brighten the screen.

If that sounds like something that would solve your problem but you have trouble getting it to work I can look for the specific tutorial I followed.

good luck

[nic_de_vera]

Been on this all night, I can sudo gedit /etc/default/grub and sudo update-grub in my sleep. Still doesn't work. Tried stuff from this thread so so far I've done:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_os_name=Linux acpi_osi=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_os_name=Linux acpi_osi=vendor acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=linux acpi_backlight=vendor"

and nothing works, the function keys do nothing, Settings, Brightness doesnt work either. GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_os_name=Linux acpi_osi=" is the closest to working, I get some response from the function keys and I can bring it down to about 80% brightness. xrandr works for dimming but isn't persistent, it's right back at max brightness after restart. Tried Brightness Control in the Software Center, I get an error "Package dependencies cannot be resolved brightness-controller: Depends: python (>= 2.7.1-0ubuntu2) but 2.7.5-5ubuntu3 is to be installed
Depends: python-wxgtk2.8 but it is not going to be installed

I've seen bug threads that say this is fixed, maybe if I update to Ubuntu 15? I'd like to make this Asus my main machine, but the brightness is hard on the eyeballs.

[NoWayWin8]

Does the brightness slider work? (its on "Brightness & Lock" in System Settings) For the grub file, have you tried just GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi="

[nic_de_vera]

Sys Settings, Brightness & Lock, I can move the slider around but it does nothing. When I'm on GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_os_name=Linux acpi_osi=" and I press fn+F5, the indicator shows on the upper right, brightness goes down to 80% and doesn't go down any further, and the slider in Brightness & Lock follows.

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi="

Ok that works the same, can bring it down one click.
Looking into xbacklight

[NoWayWin8]

What shows up under sys/class/backlight ?

ls /sys/class/backlight

[nic_de_vera]

ls /sys/class/backlight
outputs "acpi_video0 intel_backlight"

Saw some Youtube stuff on this, I can setup a xorg config file, seems complicated.
Yesterday I tried xbacklight and pretty much gave up, did xbacklight -dec 50 then xbacklight -get, the number wouldn't even change. Figured that's it, game over, this sucker's just really locked into max bright, less tha ideal but hell, I can live with it.

Today I do xbacklight -dec 50, check with xbacklight -get, the number goes down but the screen doesn't look different. Will try restarting. God I've missed Ubuntu yakshaving. Not.

[NoWayWin8]

ls /sys/class/backlight outputs "acpi_video0 intel_backlight"

Ok try GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=intel_backlight" in /etc/default/grub. By the by, does this computer also have an Nvidia graphics card in addition to Intel?

[nic_de_vera]

"quiet splash acpi_backlight=intel_backlight" does nothing, no applet in the corner. There are several confusing versions of the Asus X200MA, looking at online specs at the same low pricepoint, this may have Nvidia. So "quiet splash acpi_backlight=nvidia_backlight"?

To clarify, I don't really need functioning brightness keys, any hack that would just have this permanently fixed at, say, 10% brightness would be great, I would thank the software gods and burn an offering in thanksgiving.