You arrive on the call for Thermador wall oven. Complaint: F34 error code-- cooling fan rotation problem-- shown on the display when the oven is turned on. As a black belt in the martial art of schematic-fu, you pull up the schematic on your tablet computer. With one simple move, you identify the exact cause of the problem with ZERO disassembly.  Question: What slick move did you make to identify the specific cause of the problem with ZERO disassembly?