Our RCA refrigerator is no longer getting cold. I went through a couple different checks. Checked to see if the drain tube was blocked, it wasn't. Cleaned off the dust and everything off the condenser area under the fridge, pulled the back panel off the inside of the freezer to access the evaporator, I heard it start to defrost and no large amounts of ice buildup in the freezer. The time i noticed was last thursday. On tuesday the fridge door was left open while we were at work and I noticed the fridge doesn't cool down at all anymore, and the freezer is taking quite a bit longer to freeze ice cubes. Also, the evaporator fan doesn't spin at all I don't believe. Is there anyway to force it to spin, could this be the problem? Is the evaporator fan wholly responsible for getting cold air into the refrigerator? We don't have the money for a new fridge even though we need one. Any help would be much appreciated. Thank you!

I would first make sure the evaporator coils have light frost over the entire evaporator.
If good, replace the evaporator motor AP2071792. If you can do mechanical things, use a SM999 (AP4503254) motor at 1/5 price