Hi In fact, I eventually DID discover the likely problem. Loose floating bits of rust inside the cooling unit. We were able to get the fridge to cool temporarily by vibrating the absober tank (we used a sander) whenever it would settle. This bought us enough time to hunt down and buy a refurb fridge, as the price of replacing the cooling unit vs an entirely new fridge was pretty comparable, considering no one in our part of the world works on rv fridges, so we were on our own for repairs. Ironically that exchange created a whole new challenge, in regards to the converter not having enough juice to run the newer fridge. All good now, though!