The temperature settings for the freezer and refrigerator (values from 1 to 7) change independently (i.e., without human input) and eventually become null (indicated by a hyphen "-"), which turns off the compressor. Sometimes, I can reset them with the up/down buttons, which starts the compressor, but they shortly (a few seconds to a few minutes) revert to null. Other times I cannot reset them (they either stay null when I press the buttons or flash on to 1 or 2 and then back to null). Most recently, I pressed and held both up buttons for a few (3-7) seconds, and the settings held at 1. I then adjusted both up to 4, and they have held that way for 30+ min. (so far), and the compressor is running and it's making ice. So what's happening here?

Rich
Please belay that last message about the flashing zeros.
I found a "Control Board Diagnostics" discussion (Refrigerator Control Board 12784415 Diagnostics) that also included instructions for the Programming Mode for the control board, and I discovered that I needed to enter the proper program code (the flashing zeros apparently were telling me that there was no program code set in the board). Now programmed, it seems to be working properly (at least it has for the last 30 minutes). I ran the diagnostics and all came out good. Actually I did that with each board (old and new) and the results were the same. Although the old board showed the diagnostics cleanly, it started doing its number shifting after a while. So, I'm good now (fingers crossed). Thank you for the advice.