Asus Eee pc 1005peb screen really dark despite brightness set to full

I had the same problem with my Asus Eee PC 1001PX. The solution was to add acpi_osi=Linux to the computer bootup kernel options.

The bootup kernel options are controlled by the GRUB boot loader. You need to edit the grub settings at /etc/default/grub to have the following line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=Linux splash"

After editing the file, you need to make sure you run update-grub for your edit to take effect.

Hopefully this same solution works for you. If it doesn't, you can also try adding the option acpi_backlight=vendor to the same line which was also suggested to me when I tried to get the issue fixed.

Some BIOS's are buggy - for example, this bug-report mentions that a recent BIOS revision fixed brightness issues (revision 1202). Suggest check the vendor website and install the latest available BIOS revision.

Even with a BIOS update, it is worth checking whether the standard eepc grub options still apply to your model

Try adding either acpi_osi=Linux source or

acpi_osi=Linux acpi_backlight=vendor source

i.e.

gksu gedit /etc/default/grub

add to the values above to GRUB_CMDLINE_LINUX_DEFAULT

save

sudo update-grub

What you have described may point to general power-management issues.

Have you installed the jupiter_0.0.50.2_all.deb package on sourceforge? More information about this can be found on WebUp8.

What do your settings tell you in /etc/laptop-mode/conf.d/lcd-brightness.conf

The lcd-brightness module allows you to control the brightness of your LCD screen.

   CONTROL_BRIGHTNESS
             When this option is enabled, laptop mode will adjust your LCD
             screen’s brightness settings, if possible. You must configure
             the following settings for this to work.

   BATT_BRIGHTNESS_COMMAND

   LM_AC_BRIGHTNESS_COMMAND

   NOLM_AC_BRIGHTNESS_COMMAND

   BRIGHTNESS_OUTPUT
             The  BRIGHTNESS_COMMAND settings specify commands that should
             be executed in order to set the brightness of your  LCD.  The
             BRIGHTNESS_OUTPUT  setting  specifies where the output of the
             command  will  be  written.  For  instance,  if  your   LCD’s
             brightness is adjusted by writing a numeric value 3 to a file
             called /proc/brightness, you should set the command to  "echo
             3"  and  the output file to "/proc/brightness". If your LCD’s
             brightness is adjusted using a utility  like  "toshset",  you
             should  include  the  entire  toshset  command  line  as  the
             command, and set the output file to "/dev/null".

Update for 13.10, kernel 3.11.0-19-generic, 32bit.

I have a 1005PE:

    Manufacturer: ASUSTeK Computer INC.
    Product Name: 1005PE
    Wake-up Type: Power Switch
    SKU Number: 1005PE
    Family: Eee PC

with BIOS:

BIOS Information
    Vendor: American Megatrends Inc.
    Version: 1202 

and it works without any kernel command line parameters

[:~] % cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-3.11.0-19-generic root=[...] ro persistent quiet splash vt.handoff=7

(I do not know what persistent do --- maybe a remnant of some old test).

I do have a couple of drivers running, but they are doing that automatically --- they are loaded by the kernel without further help:

85% [:~] % lsmod | egrep -i "eee|asus"
eeepc_wmi              12983  0 
asus_wmi               23495  1 eeepc_wmi
sparse_keymap          13708  1 asus_wmi
video                  18777  2 i915,asus_wmi
wmi                    18590  1 asus_wmi

The laptop works ok (although better with xubuntu than the full fledged version); backlight, sound, suspend --- all the hw is working flawlessly.

it'a one abnormal behaviour on asus eeepc notebook with Fn brightness keys on ubuntu 14.04. when you press Fn+F5, or Fn+F6 keys to change brightness, brightness jumps almost twice. it's said about, it's a matter of performing brightness change action first by acpi and after that by Xserver, so the result is, brightness changes faster, in larger steps than you like or expect. for me have worked one slighlty different solution, change line at /etc/default/grub as many authors suggest, but insted of acpi_backlight=vendor use acpi_backlight=off use as well acpi_osi=Linux otherwise brightness change will not works totally.

There's no need to install laptop-mode-tools or other packages... but this will cause, brightness change information slider doesn't appear as before (Xserver action is not performed), but brightness changes in normal, BIOS supported steps, it seems to me it's 10 steps at asus eeepc. maybe this can be solution on more problems you've posted.