Not defrosting and motor/compressor running constantly

Bottom Freezer, several years old.

Things are cold in the freezer and fridge.

A month ago or so I noticed that the refrigerator was always running (I could hear it). More recently, it won’t defrost so we have a buildup of ice in the freezer area.

When I go to the model number on the site and type in the symptom that best matches, it says the control board. That seems like a rush to judgement but I am not a refrigerator/freezer expert.

Any other ideas? The control board looks very easy to replace but it is expensive.

Is it worth also trying to reprogram the control board?

Thanks.

If you are gaining frost on the back wall of the freezer, its a defrost problem. There are 3 main parts in a defrost system… the defrost element (it gets hot and melts the frost om the evaporator coils), the defrost thermostat or defrost terminator (it is temperature sensitive part that stops the defrosting if it gets too warm or if it breaks, it keeps the defrost from happening), and the defrost timer. The defrost timer used to be a separate part, but nowadays its part of the main control board.

So replacing the board may not fix the problem. Something else could be wrong.

The frost is in the door, front, sides and back. Does that help narrow it down?

The unit is probably 7 years old. The gaskets are intact.

Thanks.

Okay, so I put in a new control board. 24 hours ago. There is still a little bit of frost appearing on the inner part of the door but maybe it is less.

Question: If the control board was bad and it now has a new control board, do I have to remove any ice buildup from the coils?