Chromebooks do not fully shutdown, when you power them off. A little bit of power is still being used.
This would be the first thing to try:This can sometimes fix the screen doing weird things, WiFi that isn't working.
Basically: Clean install from the Chromebook's reinstall partition.
Only do this if you have at least 50% charge or the charger is plugged in. Any installed personal games on your personal account will need to be reinstalled.
Install from a Flash Drive
If your Chromebook is demanding a reinstall