Laptop is on, but screen is black.

This morning I went to close the screen on my MBP while the computer was still on to put it in sleep mode, and as soon as I closed it, I remembered something I had to do and I opened back up quickly, and the screen was black. Absolutely no light whatsoever. All the buttons still work, and I shut down by holding the power button. I even tried removing the battery, but after all that, when the computer turns back on, the screen still won't work. Help please!