echo 0 | sudo tee -a /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/brightness

cat /sys/class/backlight/intel_backlight/brightness

sudo su -c "echo 2070 >/sys/class/backlight/intel_backlight/brightness"

xbacklight -set 0

echo 0 | sudo tee -a /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/brightness