I had this same problem and fixed it today. Boy was it a pain in the butt! The issue is with the push button on the "Control PCB". It appears that one of the legs in the switch no longer connects or shorts and it causes it to trigger the "Convection" button instead. The fix is to replace that switch or order a new circuit board. I ended up un-soldering the button used to switch from °F to °C and swapped that switch with the On/Off switch. Here's how to get to that board (you'll need hands and arms similar to that of an 8-year-old child): (1) Start by flipping the toaster oven over and removing the feet. (1.1) There are two screws on each foot and another two in the middle (1.2) The plastic part is slotted and will need to slide back in place when you put it back together. Keep this in mind for the re-assembly portion. (1.3) After you have the feet off, remove the screws underneath that they were covering up. There is one screw in each corner on the bottom. These are the only screws you should need to...