I found the solution!!
After several weeks of searching I stumbled on this:
"This is a repair service for a KitchenAid refrigerator control board, part number W10219462 or W10219463 that is having problems with the evaporator fan, condenser fan, and/or cooling fan. This problem can sometimes cause the control board or refrigerator to beep."
from:
https://circuitboardmedi...zk7NgkmouDEaAreTEALw_wcBThose were the symptoms, I had been seeing/hearing - fans start and stop at unexpected times, and there is a beep when they do!
It sounds like this is a common problem, otherwise there wouldn't be a repair service just to deal with it!
The cricuit board is mounted on the back side of the fridge, near the outer wall!
It's got a beeper on it - the source of the beeps I've been hearing when the fans shut off!
That Circuit Board Medics company even made a video showing you how to get the control board out so you can send it back for repair.
https://www.youtube.com/watch?v=ALgVAq6CY60I elected to buy one of their rebuilt boards, and then send mine back to them after I had made the swap.
I replaced the circuit board and that fixed it!
It's not beeping and shutting off the fans randomly. It's cooling great and making lots of ice.
Of note, on the circuit board I removed from my fridge, I noted it had all Chinese (Taiwanese) capacitors on it and that one of them (C32) was puffed - a sign the capacitor had failed.
When I got their rebuilt circuit board, I noted all the parts they had replaced - all the Chinese (Taiwanese) capacitors, all the relays and an opto-isolator chip.
They replaced all the Jamicon capacitors with Panasonic capacitors.