GE freezer works sometimes

I have a ge refriderator with the freezer on top. Its about six years old.Just recently the freezer stopped working for some hours. It comes back on and refreezes the semi-thawed food.Everytime I think its ok it stops working again.Not sure what to do.Maybe an easy fix? Any advice would be great. Thanks

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 defrost timer, defrost heater, defrost thermostat. http://www.acmehowto.com/howto/appliance/refrigerator/refrigerator.php
In most newer models the timer has been replaced by an electronic control board. If the heater and thermostat are ok it’ll be the control.

I need your model number to know what you have.