[srw3359]

i have removed the back panel of the freezer and the whole thing is covered with ice. i am thawing it out with a hair dryer. will i need to replace something after it is thawed, or will it work on its own?

[woodchuck]

It will work until the ice builds up again.

If the evaporator coils behind the back panel of the freezer are icing up because of auto defrost failure that will stop the circulation of cold air and eventually affect the freezer too.
check the defrost heater, defrost thermostat Refrigerator Repair Guide: How To Fix a Refrigerator - ACME HOW TO.com

In most of the new units they now have the evaporative defrost control instead of a defrost timer. It senses when to defrost based on how many times and for how long the door is opened. It's more energy efficient but there does seem to be lots of problems with the board.
Here's a diagram and info on the control board installation.