Just do a search on "RS2545SH", and you'll find threads that talk about this issue. Open up the one titled "Refrigerator side not cooling", and you'll find out what to look for, especially my reply that I posted there yesterday (4/18/2010). Even better is to download the service manual I gave the link for and print it out.

But my first question is: why didn't you take off the panel inside the refrigerator? You have a dual-evaporator system, so there's an evaporator on the refrigerator side, too. Forget what's happening in the freezer, though it does prove that the compressor is working fine. You likely have icing on the evaporator in the refrigerator side, which is either due to the defrosting cycle not working (which will block all air flow once it fills with frost/ice) or the blower fan not blowing, which will keep the cold air from recirculating.

If this refrigerator worked when you first got it, I'm guessing a build up of ice and unfortunately, I'm also guessing that it is do to the defrost element no longer working. But it's a great refrigerator and is work fixing it if you can do the work yourself. You don't have to -- and shouldn't -- cut any Freon-containing parts to fix what ends up being bad, but it will take some time, especially if you do what is described at Samsung Refrigerator Heater Repair (RN's site)

Good luck!