Jadi ceritanya punya notebook baru nih.. ihirrrrr.... si tombol brightness di keyboard itu gak mau fungsi.. Itu lho kombinasi tombol Fn + Panah. Jadi gimana caranya biar bisa fungsi.? Gini

$ sudo gedit /etc/default/grub

*itu tanda dollar jangan ikutan diketik!

Terus cari baris ini:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Tambah acpi_backlight=vendor setelah quite splash jadinya nanti seperti ini

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Terus filenya nantinya seperti ini

# If you change this file, run ‘update-grub’ afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n ‘Simple configuration’

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor”
GRUB_CMDLINE_LINUX=”"

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD …)
#GRUB_BADRAM=”0×01234567,0xfefefefe,0x89abcdef,0xefefefef”

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo’
#GRUB_GFXMODE=640×480

# Uncomment if you don’t want GRUB to pass “root=UUID=xxx” parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY=”true”

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE=”480 440 1″

Terus save, terus jalankan perintah begini:

$ sudo update-grub

Restart, dan cobain tombolnya. Kalau berhasil pasti berubah brightness layarnya. :D