There are two possibilities and both are bad news.
Either the sensor itself has gone bad or the pathway from the sensor to the LCD has gone bad.
If the sensor has failed you should be able to see some old picture files (on the memory card) you have taken in the past.
It is time to call Canon Service and find out what it will cost to repair the camera.
There is no picture in the LCD and when I take a pic it goes thru the motions but the picture is black. I do get all of the menus and displays in the LCD. Recharged the batteries and re formated the card. Any Idea what could be wrong? I think the shutter may be stuck closed but don't know for sure.