Camera does not work, locks up phone and then restarts.

[tw1976]

Razr Maxx HD, have not downloaded a single extra app or widget. Recently, what has been happening is when I press the icon for the camera, the camera screen comes up, but everything is black, no clicking, but options are on left of screen for flash and the like. After about 10 to 15 seconds, the phone will lock up and then automatically restart. Between that time, I can return to main but this happens every time. Hard reset did nothing. If this has a known fix that one can do alone, please dumb it down for me. I'm not tech savvy when it comes to navigating through these things. Other than the camera issue, the phone has performed well. If busted, no worries about returning it. I did not drop the phone, either. Thanks in advance!