Hi, thanks for using JustAnswer.com. Please remember, I do not get paid for my time and expertise until you accept. F10 indicates an issue with the resistance of the temperature sensor, specifically that it thinks the oven is too hot. You can measure the resistance of the temperature probe to verify failure of the probe, if you have an ohmmeter. It should be around 1070 ohms at 70* F. If you don't have an ohmmeter, you would likely be safe simply replacing the probe. It is inexpensive and easily replaced.