canon xh-a1 suddenly showing color bars in record mode

Have just turned the camera on for first time in two weeks, and i'm getting color bars in the viewfinder when in record mode. Won't go away when I hit play. The tape that is in there is fine as far as i can tell. As far as i can see, nothing has changed in any of the settings since i used it two weeks ago.

Any ideas why a Canon xh-a1 would do this?

Much appreciated.