Our Dometic just died. I turned it on four days prior to our departure date and on the morning before it was still showing 68 degrees on the internal thremometer. According to a post on another newsgroup, there's a good check to see if it's dead.
Apparently, if the cooling unit springs a leak, there's a reaction between the ammonia cooling fluid and the propane powering the system, that produces sulphur. If you open the outside panel and see a ring of yellow flour-like powder at the base of the flue, the cooling unit is dead. The ammonia has leaked away.
The general consensus is that, if you're going to get professional repair help and your fridge is more thah 10 years old, it's better to replace the whole thing rather than just the cooling unit. Labor costs are much greater to replace the cooling unit than to install a new fridge, and the delta for the new fridge is only about 10%.
We'll be getting our 11-year-old fridge replaced next week.
Frank and Eileen
No longer RVers or FR owners