I watched the troubleshooting video on this site. Checked each part for continuity in the thermostat (which I was the most concerned with since I had to cut the wires and then rejoin them), the fan, and the heater. I ended up replacing the defrost timer. I didn't receive instructions with the timer and they are critical! There is an additional wire on the new timer that has to be placed onto one of the prongs. Depending on the wiring diagram for your particular timer the extra wire will be on the different prong. Fortunately, AppliancePartsPros is top-notch! I reached out in a chat on a Saturday and described my no instructions situation. Helen was able to send an electronic version to my email within minutes. I had to read them several times along with the diagrams, but I finally figured it out! Thanks for a great company!