Optio 555 - problem with horizontal black bands in photos

My Optio 555 has been great for the last 8 months. Yesterday, for no apparent reason, I started getting horizontal black bands through my photos. The bands appear after I snap the photo and view the result on the lcd. The camera has had no trauma whatsoever. I have cleaned the lens, switched SD memory cards and reset the camera to factory defaults. No change. I would appreciate any ideas. Thank you.

Ed Hahn