Hi. My name is Rick. I'm a camera repair technician with over 20 years in the business and I'll be glad to help you with your question today, but I'll need to clairify a couple of things first.
The D80 is a Nikon model and there is no error code FUU. There is, however, an F00 code that means the camera isn't reading the lens aperture information. Make sure the lens is set and locked at the minimum aperture and let me know if the error still occurs.