Can you please turn on your camera, and press the INFO button repeatedly - waiting a few moments between presses? It is possible that the button has been pressed and has gone into black mode.
Likely John is right, but before you do. Have you browsed through the manual and reviews all references to the LCD display and how it is used? In particular, I am looking at P272, but there are other references that might help you. I suggest downloading the PDF version HERE of the manual and doing a search for LCD.
OK, then looking at the VF, or by following the manual blind, follow the instructions in the manual to do a factory reset of the camera. That should reset anything you have inadvertently set.