I too, have a Norcold. My JAYCO is an 07. Occasionally, usually when changing power sources, the fridge will warm up to the loosing food stage for some period of time. The freezer seems to remain cold. I have taken the opportunity to defrost the freezer, which had accumulated to just over 1/2". I have used the diagnostics on board, mainly to watch the fin temp. This last time was after performing flawlessly for seven months. The diagnostic showed a thermistor fault, so I replaced it with a spare I ordered the last time it faltered. Still can't say for certain, what causes issue.
Smell is something I had to deal with as appliance tech for 35 yrs. the trick is finding a smell you like better than dead fish (not difficult!), and saturating the effected area more than bad smell. Clean immediate area with baking soda solution, bleach, or vinegar. Then load up room with Fabreze, room deodorizer, Lysol spray, etc. stay at it till you think bad smell is gone, then wait a couple days and re-do the good smell treatment. Usually works, good luck, and Happy Camping!