David D Avondale , AZ October 14, 2015 Appliance: Kenmore Refrigerator 79577546600 Kenmore Refrigerator 79577546600: Intermittently the refrigerator and freezer went into defrost mode also the light would delay coming on. How to replace Main Pcb Assembly. I replaced the circuit board assembly due to prior experience with the light issue of staying on all the time. I decided to also replace the compressor capacitor keeping the original for backup. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes