GE refrigerator TBX19JASPRWH, top freezer, bottom fridge: found water on floor running everywhere coming from water pooled under crisper drawers and running down backside of fridge wall. I assume the defrost tube is clogged but I can't find the top of the tube or where the water is suppose to drain from freezer down. How do I find the start of the tube? What panel has to be removed in the freezer to find the tube entrance please?