Have to agree with Fred.  Symptoms like yours are often a case of an ice-plugged defrost drain in the back of the unit.  Should be easier to rectify than the hard-to-access @*#! drain system on our home Samsung-built GE.  
Putting contents in a cooler under ice while the fridge is shut down to let the drain thaw, hot water dribbled slowly down it, and/or patience with a hairdryer on the drain are all possible.  But the hairdryer technique can warp plastic panels and parts and I wouldn’t go that route.  As Fred suggests, consult Dometic first.
Joel