Refrigerator & Freezer Not Cold, Freezer Coils Frozen

[jburke0000]

Model Number:
Brand: Brand
Age: Less than 1 year

Model Number: GSH25JSDBSS
Brand: GE
Age: 1-5 years

My refrigerator stopped cooling as well as it normally did. When we removed the back panel, the freezer coils were covered in ice. We defrosted it with a dryer, seems to be working better but my father said it will happen again. He said it sounds like the defrost timer isn't working. So, after some research we discovered this model's defrost cycle is controlled by a panel. We ordered the panel. Just hoping this is the correct part PS3496898, does anybody have advice on if this is what is broken? Thanks!

[denman]

Could also be the defrost heater and/or the defrost thermostat.

The heaters are usually around 20 ohms.
The defrost thermostat should be 0 ohms when frozen.

It may also be the thermistor but I do not have specs on this.

[jburke0000]

Could also be the defrost heater and/or the defrost thermostat.

The heaters are usually around 20 ohms.
The defrost thermostat should be 0 ohms when frozen.

It may also be the thermistor but I do not have specs on this.

Thank you! Hopefully the panel works, but at least we can test the other items you outlined if it doesn't.