Three years ago, the refrigerator side of this dual system fridge was not cooling. After a false diagnosis, it turned out to be the defrost heater, and that was replaced without replacing the evaporator.
Last week the refrigerator did not cool, same repair guy (who correctly diagnosed the defrost heater) said it was the control board because upon power up the compressor only ran for a minute and then shut off. The control board was replaced 4 days ago (repair guy says that when he left the compressor was running after 10 minutes), but still the refrigerator is not cooling, freezer is working.
I am 4 hours away from the fridge so cannot do diagnosis myself.
What else can cause this to happen?
Has some part of the refrigerator defrost system failed again?

The only technician who will look at the fridge has no idea of what is wrong now after the control board was replaced and feels he will have to talk to Samsung to figure out what is wrong.