I have a Dometic RM 2820, there is power to the fridge, there is also power to the switch panel on top, however, the fridge will not turn on with AC or gas?

SOURCE: Dometic rm 2612. Shuts down on gas.

Ron;
Check the burner assembly. 1 screw, remove the sheet metal cover and clean it. The burner collects rust. This is the likely. Other issues would be the gas pressure usually checked with a manometer. Should 11" of water column. If your furnace works good then the gas pressure is probably ok. Also could have a faulty ignitor which sends a miliamp signal back to the circuit board. Check the burner first, after that leave the cover off and turn the fridge on. Watch the ingnitor attempt to lite the burner. Be sure the spark is going to the burner and not shorting out on the sheet metal it is mounted in. If it is shorting to the frame the ignitor needs replacing.
Thanks for using Fixya
Jerry

SOURCE: operates with gas, does not operate with AC.

Check the heater element for power.

SOURCE: Freezer working, fridge isn't.

It is possible that your cooling unit is failing due to a blockage. The solution used to cool starts at the top of the fridge and works its way to the bottom. If there is a blockage in the cooling unit it could produce the symptom you have explained.

SOURCE: Dometic Rv fridge will get cold on a/c power but

does the flame ever got out if not ,the tsat is not the problem. It could be that the flame is not hot enough or the flue has a restriction

SOURCE: I have a Dometic RV fridge that wont get cold. it

It sounds like your cooling unit is going out. Here's a couple of things to check. Do you smell any ammonia when you open either one of the doors? When you look at the rear of the fridge, do you see anything that looks like rusty water that has run down any of the metal tubes and dried up? If the answer to either one of these is "yes", then youll need to start looking for a new fridge or replace the cooling unit on the one that you have.