I cannot change the bright in the laptop Lenovo Z470

[4l0ns0]

I´m new user in fedora 17 Security Lab, is excellent, but it is killing me, the bright desktop, in my laptop.
How can change?

and tested this tip:

start-up configuration 'GRUB2', and adding at the end of the line 'GRUB_CMDLINE_LINUX' and within their quoted, the following:

$ su -c 'nano /etc/default/grub'

GRUB_CMDLINE_LINUX="......... acpi_backlight=vendor acpi_osi=linux"

save the changes and reconfigure the boot loader again:

$ su -c 'grub2-mkconfig -o /boot/grub2/grub.cfg'

and nothing happened.

Then this:
yum reinstall bash.

and again, nothing happened.


any help is valuable.