Both oven elements stopped heating the other day. I started to troubleshoot by checking the thermostat, fuse, and power line - all checked out. Then I checked the bake element at the contacts on the back - it was getting 220V. I checked the inside and it was getting hot. I put the stove back together and set the bake temp to 350 and it heated up. Later that night, my wife tried and it stopped heating again. At this point, I believe that the main circuit board is going bad. Any suggestions?