If the freezer is cold and the fridge is hot, logic would indicate that the fan blowing the cold air from the freezer into the refrigerator is not working. Searched the ApplicancePartsPros.com website for a fan in the freezer compartment and found the video on how to replace one.
Followed the steps in the video to get the freezer partially disassembled and found the whole back of the freezer frozen over. Plugged the refrigerator back in and verified that the fan was not working.
Unplugged and after defrosting, plugged back in and the fan was still not working. Removed the original fan assembly as described in the video and tested it with a multimeter to confirm the lack of continuity in the motor windings. Testing the new fan motor with the multimeter showed the expected minimal resistance.
Have always had water leaking issues and ice build-up. While researching the fan problem, I noticed a different drain pipe part and watched that video as well. A little more internet searching convinced me that replacing our old-style drain pipe would probably fix that issue as well.
Ordered on Sunday. Parts arrived on Wednesday. Installed and back to normal that evening. Freezer at 0F and Fridge at 40F.
Since I'm a 60 yr old desk jockey, the most difficult thing about the task is the physical gymnastics (getting on the floor, sticking my upper body in the freezer, etc.) needed to do the work. It took about 2 hours to carefully get things taken apart. Installing the part and putting everything back together was less than 30 minutes.
Could have ordered parts "cheaper" elsewhere, but I've had friends who've been burned by counterfeit, non-working, or incorrect parts being received. This is the third time I've used AppliancePartsPros.com in the last 15 or so years and they have never let me down.
The fourth time will be on the next task -- replacing the door gaskets. But I'll wait until winter so I can store my food outside while I complete the repair.