Freezer freezes OK, frig compartment doesnt get cold

what is the model number of your refrigerator take a hair dryer and melt that ice and see if that will get the vent open

Appliance 911 Sea Breeze

Since the temperature is already 40°, the cold control is satisfied and will not run. Thus the freezer will warm up to 40°.

I have to assume you mean on the top shelf of a refrigerator. If so, then you need to look for the air vent(s) that are usually in the rear of frig compartment either on back wall or under the frig compartment ceiling. These vents are pouring very cold air from the freezer and the air needs to get distributed throughout the frig, however the coldness is falling on the milk or meats that are in the way (getting hit with the cold before the air is disipated within the frig).
Three options: if the air vent(s) have a movable or directional cover, then redirect the air so it blows away from the food on the shelves. If there is no movable cover, perhaps adjusting the freezer control (not the frigerator control) to the next colder freezer setting; this will reduce excess cold flow pouring into the frig. 3rd, make a shield of plastic or metal or cardboard to divert the direct cold flow of the air vent from falling on the upper shelves.

I just worked on a FF801W which is supposed to be very similar. The defrost heater in mine was of the glass tube type and located under the evaporator. There was a bimetal thermostat clipped to the top of the evaporator and a thermal fuse (sealed in a clear plastic tube) nearby. The connections were behind a little plastic cover (2 screws) in the back wall just above the evaporator.

Mine was iced up like yours and I had to defrost it with a hair dryer. All the defrosting parts in the freezer compartment turned out to work so I now suspect the defrost timer (down by the compressor). I've marked it and I'm waiting to see if it's turning.

Your defrost element is probably faulty, this is in the freezer compartment at the back and behind a removeable panel. You should change both the element and the defrost limiting thermodisc at the same time.

sounds like your defrost timer is not working properly . Most fridge/freezers the fridge gets cooled from the cool air from the freezer . But when the defrost timer is not working properly the section between the fridge and freezer freezes up and hence doesnt allow the flow of cool air into the fridge. The defrost timer can be easily replaced. 

Check your thermostat if it is still functioning well.

Freezer stayed cold but upper compartment wouldn't. Freeze started having problems with staying cold. I just paid $377 to get the two year old evaporate fan replaced. It is located inside the frig behind the panel in the freezer compartment. It took about 15 minutes. Seems this part is part of the evaporator system but not covered by anything other than the first one year warranty. Problem solved but what a ripoff from Kitchenaid.

Here are some things you can check yourself. Does it run all the time almost non-stop? if so check the vents under the front of the frig and make sure they are clean. Aslo check the condenser coil (either in back of the frig,or under the frig)Make sure that coil is clean. The condenser coil has to have contact with the outside air in order to release the heat it removed from inside the freezer.
Make sure you frig has plenty of ventilation ( wall too close on sides and back) Hope this helped. If not then you should have a pro look at it.

Check to see if air is blowing into refrigerator compartment.If no air is blowing.It may be that the settings on your dials are not right.If they are and air is not blowing,your evaporator fan is not working,or may be obstructed.