Wait! now i look at your image i would say you've accidentally deleted or otherwise disabled your directional light.
Turn of default lighting -> render settings -> common -> render options untick enable default lighting. If your scene renders black then somehow your main light has been uncoupled form the scene. Create a new directional light and render again
From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"