Got an F9 error code 3 hours into a 4-hour self-clean cycle. The technical data sheet said the likely cause was stalled cooling fan in the control area. Replace the fan and clean/vacuum the entire control area. The hardest part was removing all the wires from the control board to get it out of the way. Be sure to either take lots of pictures of where all the wires go or make yourself a sketch.
Heard clunking sound as the convection fan was cycling off. Discovered that the fan blade was loose on the motor post. Replace the fan nut. The trickiest part was having to discover that the fan nut is reverse (left-hand) threaded. It sure would have been nice if the technical data sheet warned me about that!!