Your unit has a thermal cutoff that will have to be replaced. They are not expensive but, to me, they are irritating. They trip when the temperature is too high and used to be resettable but that was too simple. This is the reason that both bake buttons stopped working. The convection bake works off of a different element around the convection fan. The oven will have to be uninstalled to reach it and replace it. You will still be able to bake on convection but the cutoff will have to be replaced before you can bake again. I am sorry to deliver this news but it is the only news I have to give. Let me know if you have any other questions.