So my MacBook somehow slipped off the table and fell on the floor today. The table is not even that high, so I didn't think there was any damage caused. The macbook itself looks fine. I opened it up, and the screen was frozen, so I had to shut it down by holding the power button, since nothing else worked. Now it doesn't work. When I turn it on, it makes that sound it usually does when turned on, but there's nothing but a white screen, and a an icon that looks like a gray folder with a question mark on it flashing in the middle of the screen. How do I fix this? Please, any help is appreciated.