f3 on advantium microwave

ok, my g.e. advantium microwave model # sca1000hww04 started beeping the other day, with an f3 error code. i unplugged it and then plugged it back in. i did not use it. after about 12 hours, the fan kicked on, and the f3 code and beeping started again. i have looked at some different forums and heard 3 different answers from the control panel to the circuit board to the temperature sensor. any ideas?