Zoom in zoom out stopped working suddenly suddenly (by 2 users)

When i pictured certain pics it worked nicely i mean zoom in and zoom out and then i switched that off.
Next time i switched that on firstly it took time to load the greeting pic then hanged for a while.After that when i tried to click a snap the view was slightly blurred and it finally hanged.So i switched that off.When i next time restarted the LCD screen went off but the lens didn't.Since then the zoom in zoom out not working.
i anticipate a good solution from your side.

Thank you