CONTROLLER

First, unplug the cord, open the freezer door then unscrews 6 screws of the back cover inside the freezer. Replace the defrost thermostat. Second, on the back in the bottom you'll see the controller which connects to the compressor then unplug the wire to the controller and use a screw driver to take the controller out and replace with the new ones. That's it. Most of the time you just replace the defrost thermostat, but in my case I did try only the defrost once but it didn't work that's why I have to replace the controller too. Now it is working fine.