After cleaning, my convection oven does not work anymore. I get an error message of F7E0 after 30 sec. and then the oven shuts off. Had a techn. look at it and he said I would need a new control board. He didn't even have the error code in his repair manual and said if the control board doesn't fix that I would have to get the whole panel including the control board again. I guess I'd be looking at about 750.00 dollars. Please help!!!!