I recently purchased a Lenovo IdeaPad Y450 Laptop, but the screen brightness was not being adjusted when I used the proper key combination (FN+UP/DOWN). The key combination did show the brightness bar, but did not adjust the actual brightness on the (LED) LCD. To fix this, edit /etc/default/grub:
Change:
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”
to
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash nomodeset acpi_backlight=vendor”
Then run
sudo update-grub
And restart!
#1 by ianfas on January 17, 2010 - 2:07 pm
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thanks a lot dude!
this works also for the lenovo ideapad u350.
#2 by brett on January 17, 2010 - 2:16 pm
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I’m glad it worked.
#3 by brett on January 9, 2010 - 1:27 pm
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Are the FN Up & Down keys the designated keys for adjusting screen brightness on your laptop?
#4 by Deepak on January 9, 2010 - 1:20 am
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I tried the same as mentioned. Updated grub. Everything ran successfully. After restarting, still the Fn+UP/DOWN keys is not changing the brightness. Should I replace vendor with some actual hex value?
#5 by JustinY on December 28, 2009 - 6:46 pm
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Thank u very much, the problem solved.
Thanks for the post
#6 by brett on December 28, 2009 - 6:15 pm
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Is that error when you are attempting to edit the settings file?
Are you editing /etc/default/grub as root?
Try in the terminal: sudo nano /etc/default/grub
#7 by JustinY on December 28, 2009 - 6:11 pm
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I have the same laptop the same model with you, I also have the same problem. I follow your command, but it wont let me change the grub
Warning: unknown mime-type for “/etc/default/grub” — using “application/octet-stream”
Error: no write permission for file “/etc/default/grub”
help