Alexander V Framingham , MA May 22, 2019 Appliance: LG Refrigerator LFC21770ST Lg Refrigerator Lfc21770st / Ast1lga: Refrigerator was not cooling. How to replace Thermistor. Replace the TDS (Time Delay Starter) and OLP (Over-load Protection) components. Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes