I'm running Ubuntu 13.04 from inside Windows 7 (using wubi). When I boot up with Ubuntu, I initially see a screen that allows me to select either "Ubuntu" or some Advanced Options. After I select "Ubuntu", I hear the familiar startup sound but there's a very very dim screen (nearly black). I cannot, under ordinary circumstances, navigate myself to a desktop with a screen that is not dimmed.
The brightness buttons on my keyboard do not have any effect on the screen's brightness. I've read countless threads, here and elsewhere, and I believe that I've narrowed down the problem.
First, let me list a few things that I have already tried.
(0) Yes, I understand wubi is quirky. But it's what I'm used to, so I'd like to continue using it.
(1) I had to type in "nomodeset" in place of "quiet splash" just to get access to a desktop that I can actually see and use.
(2) In Software & Updates, the "Additional Drivers" tab is blank. My computer has Intel drivers, not NVidia. So I doubt it's a driver problem.
(3) I removed lightdm, but that caused more problems, resulting in another fresh install.
(4) I've also tried acpi_backlight=vendor with no luck.
This thread: http://ubuntuforums.org/showthread.php?t=1855199 has given me the most insight thus far. As suggested by Toz, I've run the following commands in the terminal:
lsmod | grep ^i915
Which returns:i915 600396 0
sudo add-apt-repository ppa:kamalmostafa/linux-kamal-mjgbacklight
sudo apt-get update
All of which appeared to return the proper values and install the right updates, etc. However, after rebooting nothing was noticably any different.
sudo apt-get dist-upgrade
Toz told the OP to run some commands that return the values of the screen brightness. After doing so, the OP was able to correct his/her problem by editing the screen brightness value (640) into the a file using the line:
I tried the same command, but after rebooting, nothing was different. Then I took a look into my brightness files, which have the paths:
echo 640 > /sys/class/backlight/intel_backlight/brightness
sys/class/backlight/acer-wmi/actual_brightness (with a value of 9)
sys/class/backlight/acer-wmi/bl_power (with a value of 0)
sys/class/backlight/acer-wmi/brightness (with a value of 9)
sys/class/backlight/acer-wmi/max_brightness (with a value of 9)
All of which have values considerably smaller than 640, for instance. I tried a few ways to correct this:
(1) By typing...
(2) By typing...
echo 640 | sudo tee /sys/class/acer-wmi/brightness
Which returned: tee: /sys/class/backlight/acer-wmi/brightness: Invalid argument
And attempting to edit the file and change the value of 9 into 640. But when I try to save the file it says: Could not create a backup file while saving /sys/class/backlight/acer-wmi/brightness. And will not let me save.
sudo gedit /sys/class/backlight/acer-wmi/brightness
I'm fresh out of ideas. If anyone could help me hard code the proper values into these files, or help in some other fashion, it would be greatly appreciated. Thanks in advance!