Emachines E525 Backlight not working - Ubuntu 11.04

Asked by Trevor White on 2011-04-28

I upgraded my machine and now i don't have a backlight. I can see the backight works when i boot up. I goes to the "e" boot window and then the screen turns purple as ubuntu goes to start. as soon as the ubuntu logo comes up i loose my backlight. any suggestions?

Łukasz Urbański (luqasu) said : #1

I have the same problem on eMachines E525,but i tried to instal ubuntu 11.04 with using WUBI. until instalation there is no backlight next after rebot i can see GRUB i can choose ubuntu but next backligth again turn off. The same situation is when i want use ubuntu under recovery mode.

Trevor White (trevor-povn) said : #2

I love Ubuntu 11.04, but untill this is fixed i have to go back to 10.10... just beacuse it's more reliable... I may try to update again, but not remove any old packages.

James (marsrover7) said : #3

Try adding:

acpi_osi=Linux

At grub when you boot ubuntu. Press e to edit and see if you get any results. I did this to fix my back-light problems on 10.04 with that line.

And if that doesn't work, you can try the other workaround for this problem, posted in bug 765438's description.

Trevor White (trevor-povn) said : #5

adding acpi doesn't work, reinstalling and updating without updating packages doesn't work, and the work around does not work either... actually as soon as i updated the wolfgangkufner package i lost my back light on my 10.10 install... lucky that i have older kernals for both that seem to work for me. If I just boot from an older kernal I can use my computer the newer ones are just trouble.

If updating, the "acpi_osi=Linux" boot option, and running "sudo setpci -s 00:02.0 F4.B=00" all don't fix the problem, then continuing to use the old kernel will probably be the only workaround available for you until bug 765438 is fixed.

Actually, there is one other possible workaround:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/765438/comments/11

(For more information, see some of the comments posted in bug 765438 after comment 11.)

If you need assistance implementing that workaround (or any other), please feel free to post another reply here for help.

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