I agree that the problem is most likely sand or other debris impeding the lens barrels as they extend
If the camera has been to a beach, it is more likely it got sand in the lens. Point the camera straight DOWN as you turn it on and if the lens opens, remove batteries and use a vacuum or a can of compressed air to clean between the segments. Don't try to force the lens either way. also carefully bump the camera a bit on your hand or leg and possibly the detents will re-align. 40 percent of the time, these procedures will help. Good luck.
-Carl Houston