I have an LG French Door refrigerator, about 2 years old. Model number LFX2599 1ST. The refrigerator and freezer are cooling, but not enough. The refrigerator compartment is hovering around 54 degrees. When I put the fridge in test mode the fans and compressor run. I am thinking it’s the main board that needs to be replaced, but I don’t want to spend the money if there is a possibility something else is wrong. Thanks for any input!