Brightness setting not remembered on an Asus X54H

Solution 1:

1) Edit etc/rc.local and add the below line

echo 4 > /sys/class/backlight/acpi_video0/brightness

Where 4 is the 50 % of brightness. 8 is the maximum

2) reboot

If brightness still goes back to max go to step 3

3) In terminal run the following:

sudo -i
mv /etc/init.d/rc.local /root/
update-rc.d rc.local remove
mv /root/rc.local /etc/init.d/
update-rc.d rc.local defaults

If above 3 steps failed to resolve

Then add sleep 10 to rc.local

Example

sleep 10 
echo 5 > /sys/class/backlight/acpi_video0/brightness
exit 0

Solution 2:

Same problem here on clean installation.

First set your desired brightness value with your function keys.

Now you're going to identify it on a number scale by typing in a terminal :

cat /sys/class/backlight/acpi_video0/brightness

keep your value in mind and then go edit config file:

sudo gedit /etc/rc.local

and add the following line right before the "exit 0" line

echo x > /sys/class/backlight/acpi_video0/brightness

where x stand for your desired value.

This way:

.

where 4 is an example of value.

Save the document and exit, now after reboot and ac power plug it will be all fine.