Refrigerator/Freezer Fan running but not cooling

Yesterday noticed that the freezer was defrosting, refrigerator seemed okay. This morning fridge is also warming. We can hear the fan or something running, light is on. Cleaned the coils, which were quite dirty, and also left it unplugged for about 2 hrs to see if it would reboot somehow. No luck.

Temp controls are also fine. I've read that it could be something related to defrost system, but I don't know how to check that. It's model # WRS6R3EW2. (It says White Westinghouse on the front of the unit, Electrolux on the model # sticker, and frigidaire.com on the owners manual, take your pick!)

Does anyone know how I would test the defroster components? Or have any suggestions on other fixes I could try?

Thanks!