I am really hoping someone can help you with this problem because I am having the exact same problem.
The computer seems to be stuck in in hibernation mobe after I close the screen. I have a HP pavillion dv2214usEntertainment Notebook Pc.
The only way I can get the notebook to respond is to take out the battery, press the power source for a few seconds and reboot that way. It is a drastic way, but it's the only way. If I try to just press the power source and press it on again, it goes right back to the hibernation place it was before, where the screen is black and none if the keys are functional. HELP! I don't want to fry my computer one day!