not cooling on top

This one will be interesting. This is a large french door with bottom freezer style 30.7 cu.ft. expensive type. Suddenly stopped cooling. Worked on by a qualified certified technician recommended by LG. He identified a bad linear compressor. Compressor was replaced. After replacing compressor...

Top refrigerator bottom freezer. Refrigerator is not cooling. Error code er rf. Pressed reset button for test mode once. Completed voltage check on pins 1 & 3 voltage was 2.6. On pins 2 & 3 voltage was 13.08. There is NO ice buildup fan runs in test mode. Fins do get frost on them. Any ideas or...