Ubuntu – Can’t change brightness after disconnecting second monitor

brightnessmonitorscreen

When I boot up with 2 monitors, or when I connect the second monitor to my laptop, I can change brightness of the laptop screen in the usual sense.

After disconnecting the second monitor, when I change the brightness, the animation at the top right corner seems to be changing, but it doesn't effect the screen brightness.

the value in /sys/class/backlight/acpi_video0/brightness does change, so writing there is not the solution either.

Any clues?

Ubuntu 14.04 LTS, 3.13.0-30-generic #55-Ubuntu SMP Fri Jul 4 21:40:53 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Thanks in advance.

Best Answer

Intel graphics? Thent this is probably a known bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1308674

I found that updating the kernel helped to resolve that particular issue, but it comes at the expense of the screen not being able to be fully black, anymore.

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