Kenmor/LG refrigerator not cooling

I have a kenmore elite refrigerator 795.74043.411 made buy lg. It has had a problem with frost build up in fridge section since it was just over a year old. I would defrost and it would work normally for about 9 months. Now it is 4 years old and I got a er rf error. I took out the fan and replaced it and the fuse. I put it back together and it does not cool. No codes fans all run. I bought the service manual. I did the diagnostics and the PCB board did not pass the checks. I replaced the PCB board. It did not cool. I checked the new board, did not pass voltage check. Checked my meter, tried another meter, same result. Ordered another board, same result. Tried another board from a different vendor. Does not work. Compressor seems to run but no cooling. Thought it might be low on freon. I bought a piercing valve and borrowed professional refrigerant guage and freon sniffer. Check for freon leaks no leaks. Installed piecing valve on suction line and check with guage 45 psi at room temp when unplugged and not running. Therefore full freon. Plug in fridge and get no pressure change, do test mode 1 forced starting, no pressure change. So compressor is not running. check compressor resistance, is in spec. Finally try another PCB from different vendor, Does not pass voltage check, does not cool. I have way too much time and money in this pos. Does LG have that many problems with Control boards or am I missing something?