Saw a post earlier about a fridge on the fritz, TMM I believe? dirty condenser coil is a good place to start. I thought that on mine, till i realized it is tucked underneath somewhere. Not on the back where they were for the last hundred years. LOL
The fridge is about 10 years old and had its first 'warm spell' about 5 years ago. At some point i turned it off for a few minutes. Back on and it worked! Apparently the boards in these can be rebooted like a computer. Ive done it several times since when it feels warm.
Otherwise the next things to look at ( if not already done) would be iced up evap or a fan not working...