I watched some YouTube videos, then determined that the compressor and the fans were working. That left possibly the thermostat or the damper motor as my culprits. Since the freezer was working, the damper motor was first in line. I watched a video here on removing the damper cover and found that by propping the damper open ever so slightly, the refrigerator cooled. I ordered the part, snapped it in, and everything is working perfectly.