Default HTC vivid- camera stoped working

hello ,
i'm new here and it a wonderful forum with a lot of helping information !
i have a problem htc vivid , with no reason the camera stopde working .
when i try to set here on by clik the camera button the screen became frozen and after a 10 second there is a little vibrate and the HTC got restart but somtimes there is a white screen and i need to disconect the battery .
there are no root or somthing like this , the HTC are clean .