I am trying to find a place to ask this, I figured here would be a good start.So heres what I need to know.

Somehow the ChromeOS gets corrupt and will not recover with the USB or SD drive recovery steps. I have even tried the turning it off and on 25 times!!
Disconnect the battery worked once.

So I have four of these c300 sitting here with the same problem. They are out of warranty, when they used to be under warranty I would send them in and in about a week they came back . Same motherboard nothing got replaced, it just said the OS was restored.

I can get the answer from any tech on how they did this.

Could someone point me in the right direction on this.

Thank You so much!