my screen isn't a black screen during boot any more

How do i make screen dimming work in ubuntu 12.04

Edit your /etc/default/grub file:

$ sudo gedit /etc/default/grub

or

$ sudo nano /etc/default/grub

or

from recovery terminal

# mount -rw -o remount /
# nano /etc/default/grub

Add the options "acpi_osi=Linux acpi_backlight=vendor" to the GRUB_CMDLINE_LINUX_DEFAULT line. It should look like this:

*GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"*

original line was:

*GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"*

Update grub configuration!!!! - do not forget to do this, the configuration change will not be set up if you don't run the next command:

sudo update-grub

This worked for me after trying a lot of other solutions. I have a HP dv7-6090ef with hybrid graphics Intel/AMD.

Have fun using Ubuntu!

[THIS IS A FIX FOR LAPTOPS THAT START IN BLACK SCREEN, FOUND IT ON UBUNTU]
[WORKED FOR ME]