Your GE Arctica fridge, like mine purchased around 2002, eventually loses the ability to regulate temperature in the main compartment, and the temperature drops to near freezing temperatures. You find, on doing the service inspection of the damper mechanism (found in the service manual you found online) between the freezer compartment and the main compartment, that the damper door is not operating. Instead, it remains open although you may hear the servo motor running that is supposed to close the damper as you run the diagnostic test.
Here is a exploded assembly diagram of the fridge with the offending parts noted in red:
Also, here is a picture of the styrofoam junk that is how the entire top rear of the main compartment is built. You will have to take care to remember how these random pieces of foam are taped together to reassemble the unit:
I found that the damper door molding broke at the lower area of the damper molding which is a socket that fits into the pin of the servomotor. Here is a picture of the damper installed in the frame showing where the break occurred:
I removed the damper door and glued the bottom socket back on with epoxy, then wrapped the bottom part of the molding in cotton thread, coated with epoxy. This reinforces the pin so that it will not break again. A closeup of the reinforced bottom pin:
I reassembled the fridge, confirmed that the damper works as expected under the diagnostic test, and it is working fine again.