We have na Aeg D4100-1 Competence double oven. it appears that the temperature control in the main oven is working, but the fan is not. The light in the main oven is not working either. Previously , if the light did not work, we changed the bulb. The fan always continued to work until the bulb was changed. Are the light and fan on the same circuit and could this have failed? Otherwise please could you suggest what might be wrong. Many thanks.