How to Troubleshoot & Replace Ge AP2635477 / WR9X480 Defrost Timer

Replaced the Defrost Timer 

Opened freezer bottom and found completely iced up with compressor running and coil warm as normal. Also found heater burnt thru after I defrosted overnight. Replaced defrost timer and heater for under $200. All fixed !?? 

We went to the Appliance PrartsPros web site and entered the problem. The resolution for our refrigerator was the two items suggested. We purchased and installed both items and within 24 hours we saw immediate improvement... and now after more than 3 days, the OLD refrigerator is working like new again... Both the tech advice from the site and the quality parts were reasons for the success. Thanks, 

Installed timer and thermostat by repair man. saved us a lot of money for a new refrigerator 

Replaced the defrost timer and no result. Replaced the thermostat control and now everything works again. Total cost was about $50 and way below a repairman's estimate. 

Just needed the Defrost timer and it is now working and getting cold.