You can recover pictures from canon camera with camera recovery software, download this one names asoftech photo recovery that helped me beforehttp://www.asoftech.com/apr/Take note that you'd better remove the memory card from camera, and then connect the memory card to computer with a card reader.If needed, you can do a quick format of the memory card, and then use asoftech photo recovery to recover the photos.Here's a video tutorial for camera photo recovery
Can you see anything in live view? This camera has no mirror, but is still a TTL camera through a beam splitter. If you can't see anything, did you remove the lens cap?
The other possibility is that someone dropped the camera and damaged the beam splitter or other optical things inside of the camera.
Since you can see the menus, did you try to go to the setup menu, and adjust the brightness of the screen?
It is in the setup menu, the line under Sound settings. Try to make the display brighter and don't forget to ok that one, because otherwise nothing will be changed. OK with the ok / Func button.
