The refrigerator is a dometic RM 2652.
DC powers that fridge......used for circuit board, propane system, and lights
W/O DC nothing would work so you know that circuit is OK
Electric.......
Test that outlet by plugging an electric drill or a lamp into it.
IF no AC Power to outlet then could be bad outlet, tripped CB or tripped GFI
Use an extension cord and plug fridge in then see if it will run on AC Power.
If you can then take the thermistor, unclip it and let it hang down low (thermmistor is temp sensor on far right fin in food compartment)
With it hanging down low fridge will over cool and should be able to see temps in low 30s in food compartment (thermometer in glass of water)
If after at least 8 hrs then cooling unit has probably leaked.
As for the propane side......need at least 2 people.
One at backside of fridge to listen/look for signs of leaking and other one at propane valving it in slowly and ready to valve out.
Manual that covers your model