How to Diagnose Power Loss to Compressor on LG Fridge Model LMX28988ST/00?

It sounds like you're dealing with a tricky issue with your LG fridge model `LMX28988ST/00`, especially since the compressor isn't running while the fans are still operational. Given that you've already replaced the control board and the run capacitor, it’s important to check the start relay next. This small device, mounted on the side of the compressor, is crucial because it provides power to the compressor's run and start windings for a brief moment during startup. If the start relay is defective, it can cause the compressor to run intermittently or not at all, which would prevent the fridge from cooling properly. Since you mentioned that this model uses a linear compressor, it’s worth noting that these compressors often have a different setup compared to traditional ones. If the start relay checks out, then the next step would be to examine the compressor itself. It’s not uncommon for these compressors to fail even if they’re not drawing excessive amps or showing obvious signs of failure, like overheating. Additionally, consider checking the thermistor connected to the control board, as it can also affect the compressor's operation. If everything else seems fine and the compressor is still not functioning properly, it might indeed be time to look into replacing the compressor itself.