One of the most likely problems you will see on a Whirlpool made refrigerator (Kitchen Aid, Kenmore, Roper) is the display inside the refrigerator will go blank and the refrigerator lights will not turn on.  This is a common sign that the main printed circuit board (PCB) has failed.  On built-in refrigerators, this PCB is located above the refrigerator in a sheet metal box by the compressor.  For side by side refrigerators, the control board is located in the lower back right corner next to the compressor in a sheet metal box.  The PCB will need to be replaced to resolve the lights and display not working.