GE Profile Arctica - both sides won't stay cold, already replaced mother board

Our GE Profile Arctica is not staying cold. We replaced the mother board last night, but that didn't seem to help the temperature, although it did get the ice maker working again. There is some frost at the back/inside of the freezer. I don't know how to access the coils to check them.

I've read several posts talking about the damper - is this the flap that opens and closes where the ice shoots out? If so, ours has not worked properly since day one. However, we've had this fridge for ten years, and the temp issues just started last week.

Freezer temp is around 13 and fridge is around 45. I've read several posts, but am overwhelmed with trying to decipher what is the appropriate next step. I have no idea what an ohm is and I don't know how to run any tests.

Any guidance anyone can provide will be GREATLY appreciated. We've had to repair our dryer and replace our furnace this winter so I'm REALLY hoping we don't have to replace this fridge, too (especially since we just put the new mother board in!).

Also, please word your responses in elementary terms, if possible. I'm an accountant, not an electrician, so all of this is pretty foreign to me.

Thanks!