Why isn't my chromebook turning on?

My Chromebook has failed to turn on. The charging light turns on but the screen is black and it fails to respond. I have replaced the screen as that is what I thought the initial problem was. I have also tried hard resetting it and trying to force it to turn on. Someone recommended plugging it in without the battery, but that also failed. Is there anything else I can try or something I am not considering? I looked at the rest of the parts and they seemed fine.