M A, this happens most often if the camera was either dropped with the lens extended, knocking it off the guides, or if exposed to dirt/debris that will bind the lens when the camera turns on. Check the space around the lens and see if the spacing is equal distance all the way around. Sometimes you can use a vacuum cleaner and apply vacuum suction on the lens while powering it on. this may remove some of the dirt/debris and free the mechanism. If none of that works, you may have to replace the lens. The guide for that is here. Hope this helps, good luck.