Ubuntu Upgrade from 10.10 to 11.04 - No Backlight for eMachines E525

This sounds exactly like my problem. What do I do about it?

I'm marking bug 772050 a duplicate of bug 765438, which will result in this bug being a duplicate of bug 765438 as well. I'm posting this so as to prevent any confusion arising later as to how that happened, and so that in the very unlikely event that bug 772050 is later judged not to be a duplicate of bug 765438, it will be clearer that this bug maybe shouldn't be either (I think that turn of events is very unlikely, though).

I followed unknown47's advice and restarted and it worked. If you have an Acer Aspire / Emachines laptop and have a similar problem, do this: my computer is emachines e725

Bootup ubuntu.
Connect external monitor.
Edit /etc/rc.local and add before exit 0:
setpci -s 00:02.0 F4.B=00
Edit /etc/default/grub and change
GRUB_CMDLINE_LINUX_DEFAULT = "quiet splash"
to
GRUB_CMDLINE_LINUX_DEFAULT = "quiet splash acpi_osi = Linux"
Execute the command sudo update-grub2
And restart your computer.

this works until your computer falls asleep, or you log out, you must do a complete reboot for it to work again

Trevor White, this bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? If so, could you please test for this with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in the development release from a Terminal (Applications->Accessories->Terminal), as it will automatically gather and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available (not the daily folder, but the one all the way at the bottom) following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.12-rc7

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]