Here's a little snippet of info From THIS
"RV refrigerators operate by heating a sealed cooling element either with a gas flame, or an electric heating element. The cooling unit amounts to a series of tubes filled with an ammonia-based liquid. As heat is applied, the fluid circulates through the cooling unit drawing the heat out of the refrigerator."
"Troubleshooting An RV Refrigerator..
When an RV refrigerator starts failing (not cooling as well as it should), it means the fluid is no longer circulating properly through the cooling unit.
The nice thing about RV refrigerators is there are no moving parts. There are no pumps to wear out, and no compressors either. All the work is done simply by heating liquid ó like in your coffee pot. When it boils, it perks the coffee. When the ammonia is heated, it circulates.
If the cooling unit develops a leak, you will smell ammonia in a big way. This isnít a very common occurrence, but if it does happen, you will immediately know where the problem is."
"When RV Refrigerators Arenít Used
More often, the problem with an RV refrigerator is time combined with lack of use. As RV refrigerators age, the ammonia liquid can create sediment that settles to the bottom of the cooling unit. This sediment will hinder the ability of the ammonia to circulate properly through the cooling unit. As the sediment builds up, the refrigerator will cool less and less.
A refrigerator that is used once or twice a year over a period of 5 or 6 years is much more likely to plug up than one that is in continual operation. Fluid movement keeps any sediment suspended in the fluid, which ultimately prevents any accumulation from occurring.
Now we know why it doesnít
work. What can be done about it?"
"Repairing vs Replacing A Non-Cooling RV Refrigerator
It has been said that if you remove the refrigerator from the RV and turn it upside down for a period of time, it may
start working again. Iíve never personally used that method, but the theory behind it is only marginally acceptable. Once sediment exists, you may dislodge it for a period of time, but as soon as the refrigerator sits again for a period of time it will again settle and plug up the tubes. Rebuilt cooling units
can be purchased ó in effect, rebuilding your refrigerator. It will again cool as good as a new refrigerator. But here is where the problem comes inÖ
Replacement cooling units are expensive, and combined with the labor required to remove a bad cooling unit and install a new one, the cost of the project will be at or above the cost of buying a complete new refrigerator."
I've successfully used the method described above. The only difference, was that I turned it on both sides also. I also used a rubber hammer and gently, but firmly tapped the sides of the fridge. I turned it on each of the four sides and tapped whatever side was on top. I left it on each side for an hour, finally ending up with it upright.