LG Refrigerator/Freezer stopped cooling.

You may have caught it during a defrost cycle. Actually the refrigerator is cooled by the freezer.

Does the freezer part cool? if not, is the compressor running? If the compressor is running and the freezer is cold, maybe you have an ice clog that avoids the fresh air go to the fridge cabinet. To fix it, you must stop it at least for 24 hours and let it completely defrost. If the compressor is not running, maybe it is broken. If the compressor is running but not freezing any of the cabinets, maybe it is a gas leak.