I had the same problem with my Kitchenaid oven not heating. Control panel lights worked fine, just no heat in any mode, no error codes. After checking all the "easy" solutions with a multimeter -- 240 volts from wall, thermal fuse, and heating elements -- all were fine.

Upon examining the Appliance Manager (Taurus) control board (part 9761156) -- the one with all the relays, I saw that the large power relay was partly melted at the point where one of the two large 12-guage red wires plugged into it. The connector was burned and corroded.

After trying to clean the connector, I determined with a voltage meter that the relay wasn't working -- most likely burned up inside, which calls for a replacement to the entire board -- $220. Ordered one from AppliancePartsPros on Sunday night, had in my hands Tuesday morning. The new board solved the problem.:)

BTW, my Kitchenaid dual-fuel range is about 7 years old and had never been a problems until the last 12 months, during which I have had to replace all three of the major (expensive) control boards, including the display board.:(