ps vita black screen, does not update

Hi guys! I would like you to give me a light...like I have an unlocked psvita! I was putting a file of the Max Payne game!! psvita asks for an update! update! just in time

after installing the update, I turn off psvita on the off button so it doesn't update! When I try to turn it on, the screen is black! I put it on the system restore screen and I can't because it says it doesn't recognize it, I try to update it through the content manager on the pc and I wait forever!