Why is refrigerator-freezer only cooling and freezing half-way down?

Most modern refrig/freezer units have digital controls with built in diagnostics. If you can pull the papers with the diagnostics instructions from the bottom (typically) of the unit it will tell how to perform these functions from the control panel. I had an issue with my Kitchen Aid frig freezing up a while back and I simply had to defrost the unit and the problem has not recurred. I think in my case the unit sat for a extended time with the freezer drawer not completely closed leading to the freeze up and it could not recover from that condition by itself. Electronics are "smart" but not that smart. If your doors aren't sealing like they should it can lead to freeze up conditions like this very easily since it just gets more and more moisture building on the evaporator coils more rapidly than the defrost cycles can handle. Unfortunately the evaporator coils in modern units are not readily accessible. You will have to store your food in some other fashion while your let room temperature take it sweet time to defrost the unit. I pulled the cover from my coil in the lower freezer drawer compartment and defrosted with a hair dryer as we were accustomed to doing in the old pre-frost free days. Getting the coil exposed to do that is kind of a hassle though. It allowed me to get it done quickly and not worry about all my food thawing though. Either route will likely lead to puddles on the floor if your coil is indeed frozen up. Be prepared with towels/mops etc .