This board controls the operation of the unit and is located on the back of the refrigerator. The defrost controls are built-in to the control board. If your refrigerator is too hot or cold, will not defrost, runs to long, or the ice maker will not work, you may need to replace the control board. Note: This is a genuine OEM part and has been updated by the manufacturer. It may differ in appearance but will function the same as the original.