What could be wrong with my refrigerator?

Whirlpool model WRX988SIBM00 The unit is about one year old,  It's a large 28 cubic foot unit, has french doors on top, a refrigerator drawer and freezer drawer.  The freezer drawer stays frozen, the fridge drawer runs at about 37-38 degrees, but the top french door refrigerator runs at 50 degrees.  The milk is warm. I cleaned the condenser coils with a vacuum.  The condenser coils were not very warm.  The fan was still running as I could see a few stray dog hairs blowing around on the coil. I let it run all day, and it did not improve. It stopped running in the evening, and was not running the next morning.  I lowered the freezer temp to -2 degrees, and the unit came on.  It sounded ok, and it seemed the compressor kicked in. What could be the problem(s)?  I've looked at a few forums and most of the posts complain about the absolute poor service Whirlpool provides for these types of refrigerators.  So I want to see if I can fix it myself. Thank you.