Dometic Refrigerator barely cools: Model RM2652

This refrigerator is driving me nuts. Does not cool at all. 48 - 53 degrees. I installed 2 fans to circulate the air. I got the temp down to 39 degrees at night, but on a hot day, it goes back up to 50 degrees. Food spoils, aggravating. I pulled the thermostat, tried 'manual' opns, no change. The coils in back are hot. No ammonia smell. Same temp with gas or electric. Any ideas? My TT is a 2005 Model. So the box is 6 years old, and used 3-4 times a year. We're not full timers. Just throwing this out there. It is an expensive replacement if the box is kaput. Thanks All.
Road Toad

We have a 2005 Motorhome with the same problem when the outside air is over 90. Mfg says that it can only manage 40 degrees below ambient given the technology, best on GAS. WE put ICE in the bottom of the frig with a fan when the ambient is over 80, this works well. No spoilage.

I had thought of the ice trick. Anyways, I replaced the circuit board yesterday and nada. Now I don't have 12V power at the red wire, where I connect to the board. I'm baffled. I used a test light and there is no 12V there. Weird. Hooked all the tabs up and did a triple check. Must be something wrong because a 15AMP fuse in camper blew. The fuses on the board are good. Battery is good, convertor is working. Could there be an in-line fuse on red wire from battery to fridg? Doesn't seem like there should be. I may have to break down and have my RV mechanic run a check on it. Otherwise I'm out $125 for the board. Thanks for the input. BTW - Have you tried finding 'block ice' in this day and time? I bet its easier to buy and find drugs than block ice. Signs of the times I reckon. A 10 LB Block sitting in the bottom would be a nice touch.