When my Samsung NP470R5E Laptop is booted when the power cable is plugged in, the screen brightness starts out at the maximum. This behavior continues when I unplug the power cable and run it on battery.
When, however, I boot on battery power, the screen stays dim and I am unable to increase the brightness. This behavior continues if I plug the laptop in.
How can I increase the brightness after booting from battery power without having to restart and boot while plugged in?