GE F0 code wall oven

When the oven gets to the set temperature and bakes for approx. 30 minutes, it will throw a F0 code. The control panel is then locked out but the clock keeps working. After the oven cools down, it resets itself and will repeat the above. Replaced the Switch limit bi-metal, Limit switch and Sensor ASM which did not fix it. Tested the Key panel per the directions, checked Ok. Any suggestions on what is next? thanks