It sounds like the Chrome Operating System has been corrupted. You can restore the operating system by creating a recovery image. This guide [guide|150907|here|new_window=true] should give you the first few steps for creating one. When you get to the ***Identify Your Chromebook*** screen, you will want to select your manufacturer and model of Chromebook.
Once you have the recovery image ready push the ***Esc+Refresh on the keyboard, then press the Power button to reboot in recovery mode.*** Your device should prompt you to plug in your recovery image.