We troubleshot a GE Advantium Speedcooker from the control board for a no convection bake problem and determined that either the convective heating element or the TCO had failed open. Testing each component individually required uninstalling the oven with special equipment. So on our second visit, we returned with both parts-- the convection heating element and the TCO. The specific failure turned out to be the non-resettable TCO that had failed open. 

Watch how I used the schematic to select strategic voltage and current measurements needed to identify the problem. 

We did all our troubleshooting from the control board without uninstalling the oven. Doing it this way allowed us to diagnose the problem with minimal disassembly. We half-split the problem between the control board and the heating circuit and fixed the problem on the second trip when we returned with the parts. 

Troubleshooting electric circuits is easy and fun if you know how to read schematics and understand basic electricity! 

Learn how to think and troubleshoot like a real technician at https://mastersamuraitech.com/fundamentals