How to Troubleshoot & Replace Ge AP2061708 / WR9X502 Refrigerator Defrost Timer

After googling why my fridge did not work I found info that a likely cause was the defrost switch going bad..there is a way you can check it by manually advancing it. After advancing it it was the issue. I found the part priced well on AppliancePartsPros.com and quickly and easily ordered the part. It came quickly and I installed it and the problem was fixed. 

Replace defrost timer took 5 minutes..... I GOT THE PART THE NEXT DAY WITH IN 24 HOURS ***AMAZING*** part is now plastic and does not require the ground wire ...old one was a heavy all metal piece.... hope this last.... my refrigerator is only 28 years old ...lol 

First I replaced defrost timer but didn’t work, then I replaced the defrost thermostat and it worked, that was the problem, now I have an extra defrost timer, it only took me 30 minutes for both. 

Watched videos on this site , ordered parts and installed as directed (easy work). My refrigerator is working fine again. 

Tested to make sure the defrost heaters were working by manually operating the defrost timer, that checked out okay so I replaced the defrost timer. 

Replaced defrost timer, things still didn't seem correct. Found under the fan cover there was a piece of Styrofoam that hadn't been removed from the original installation 2 years ago the remainder of the opening had frozen over. Working fine now 

Replaced defrost timer 

REMOVE SET CONTROL PANEL INSIDE REFRIGERATOR TAKE OUT OLD DEFROST TIMER .PUT NEW ONE .AND DO NOT. ON .APPLIANCE. WAIT MORE 5 MIN. AND STILL OFF .SOMETHING WRONG. HAPPEN. PUT BACK OLD DEFROST TIMER DE APPLIANCE ON. EASY WORK ,DEVICE DEFECT.WE NEED REPLACE .THAN YOU. 

I ordered the timer and the heat control, both arrived in a couple of days. I looked at the videos and took notes. I installed them in less that a half hour. (and I'm a musician) and now both work perfectly. I was able to diagnose the problems by your information too. Don't know how much I saved but it was significant. Plus has a nice feeling of accomplishment Thanks 

Gasket on the door looked fine , and the defrost heater was also good. So I figured it had to be the defrost timer . Took ten minutes to replace. All good. Easy job.