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Running Ubuntu 12.04, I can't get the keyboard backlight on a Macbook Pro (mid 2012) to turn on. When I press the brightness button, the display shows up on full but the lights do not turn on. It shows full always on the screen, but they never turn on. I don't really care about getting the keys to work, but I just want something like a terminal command just to get them on. (I don't care about the intervals, I just want the backlight on!!!)

Any help is great, Thanks,


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all i need is to send like 3 volts to the LED's right? – Skyler 440 Feb 4 '13 at 13:43
Maybe a little pulse width modulation for dimmer – Skyler 440 Feb 4 '13 at 13:43
Please add what Macbook-Model you have. If you don't know, you can find out with sudo dmidecode -s system-product-name on the commandline. Thanks. – Clausi Jul 30 '13 at 7:51

The Ubuntu documentation page has the following information in relation to the Macbook.

LCD Brightness Control

The package nvidia-bl-dkms is not available for 12.04. Fortunately, the following procedure works (taken from

If backlight control does not work for you, follow these instructions:

Edit the file '/etc/X11/xorg.conf' and add this line into the Device section:

 Option "RegistryDwords" "EnableBrightnessControl=1" 

Reboot and check if backlight control works. If so, you're done. If not, edit the file '/etc/default/grub' and change the line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor" 

Update grub with this command: sudo update-grub Reboot and backlight control should work.

If it still doesn't work, try installing the nvidia-bl-dkms package from mactel-support for Natty (from, this was the only way for me to get the backlight control working on Precise. Results may vary as some people claim this driver does not work on Precise.

Link to these info is below.

Also this blog appears to have used a script to get it to work.

Best of luck!

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I'm talking about the backlight on the keyboard, not the LCD backligt. The LCD backlight works fine – Skyler 440 Jul 30 '13 at 19:36
oh, I see i just read the first part sorry – Skyler 440 Jul 30 '13 at 19:55
I don't have xorg.conf – Skyler 440 Jul 30 '13 at 20:01
@Skyler440 Some systems don't have a xorg.conf file as there is no need. You may create one. The following link is about another problem but has the details about creating the xorg.conf file… – gman Jul 30 '13 at 21:48

Found this thread in the forums, which suggest installing a program called `pommed':

pommed handles the hotkeys found on the Apple MacBook Pro, MacBook and PowerBook laptops and adjusts the LCD backlight, sound volume, keyboard backlight or ejects the CD-ROM drive accordingly.

You should give it a try.

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