GE PSS26NGPABB Fridge and freezer are warm and freezer not defrosting

Refrigerator & Freezer Repair
1

Brand: General Electric
Model Number: PSS26NGPABB
Main Symptom: Freezer not defrosting
What happens & when: Constantly not defrosting

Error Code (if any): No
Parts or tests already tried: Temperature sensor replaced and Refrigerator Defrost Thermostat replaced six weeks ago.
Photos / video link:

2

Have you tested the continuity or resistance of the defrost heater?

3

I have not. How would one go about doing this?

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You’ll need a multi-meter and to have access to the defrost heater. Your fridge is a GE and the one in the video below is an LG, so the access information is different but the basics of testing a defrost heater are the same. Go to around 3:20 in the video, that’s where it talks about how to test a defrost heater.