I know that it can be very frustrating to have issues with your refrigerator. First check in the freezer on the back wall for a frost build up. If frost is building up, it indicates the unit is not defrosting. The frost will block air flow to the refrigerator section, causing it to quit cooling. If this is taking place, you can turn the unit off for a few hours to defrost. When all the frost is gone, it will cool again for awhile. If the frost buildup comes back, then you have a problem with the defrost system. This could be with the timer or the defrost heater. If there is no frosting taking place, the compressor could be defective or the system could have a low charge or restriction. A technician will be needed to make these checks. I hope this helps. If you need further assistance, please reply to this thread. Thank you for using Manage My Life.