KBRC36FTS00, about 5 years old. At the moment the fridge and freezer are both cold, all buttons work, defroster apparently works. BUT - the condenser fan stops running every 30-60 seconds, stays off for 10 seconds or so, the control board beeps, and the fan runs again. This routine seems to repeat fairly continuously. I checked the condenser coils for dirt, and there is only the lightest coating of dust, so I'm sure that's not a factor.
Based on an internet search, this looks like symptoms of the control board going bad, but I found one product bulletin for a similar model that says the condenser fan is going bad, based on these symptoms.
Even worse, apparently the control board is NLA - if my lookup skills are correct, it's part number W10219462. The fan is cheaper and readily available to boot.
Not sure how to get to diagnostic mode - touch the cooling on/off and filter reset buttons at the same time and hold? Will this tell me if it's my board or my fan?
Any/all advice appreciated!