which of theses maxes your screen brightness
sudo basch -c "echo `cat /sys/class/backlight/acpi_video0/max_brightness` > /sys/class/backlight/acpi_video0/brightness"
or which of theses turns it dim
sudo bash -c "echo `cat /sys/class/backlight/intel_backlight/max_brightness` > /sys/class/backlight/intel_backlight/brightness"
sudo bash -c "echo 0 > /sys/class/backlight/acpi_video0/brightness"
if you have to do both just say so
sudo basch -c "echo 0 > /sys/class/backlight/intel_backlight/brightness"