May be late, but a kid at my school found a way a while back. In case all other methods fail, you can buy a new motherboard and replace it through the back. Make sure to get the right model. In case you have to return your Chromebook around the end of the school year (if you don't own it). When times come, switch out the motherboards again and pretend like nothing ever happened. It worked for him multiple times and it will most likely work for you too. May be pricey, but there will be little to no permanent damage.