We have a Maytag MZD2766GEW that is not cooling the fridge part properly. We have removed the panel in the back of the freezer and see that it is frosted right up. When we melt ice with a hair dryer the fridge works again for about 2 weeks. Could this be the evaporator fan?

Yes it could be the fan OR the fan door switch if so equipped BUT usually it is in the self defrost circuit. You have a heater and defrost thermostst(bimetal)in the freezer section and you have a defrost timmer also located in the unit. You will need an electrical tester to check those components.

More than likely your defrost system is not working. There are three parts: the defrost timer, the heater and defrost thermostat (called the defrost terminator). The last two parts are in the freezer and should be replaced together. You need a multimeter to check everything out. First, remove cover to freezer coils (unplug unit first) and you will see wires coming into freezer going to the fan and to the defrost heater. The wires going to the heater will have a t-stat wired in series and it is clipped to the side of the coils. Unplug the wires where they supply the t-stat and on the other side where it supplies the other side of the heater. Keep these wires away from the coils where you can test them with a volt/ohm meter. Find defrost timer and turn it until it clicks and put meter on ohms and see if you have a reading of about zero from one side of the plug to one wire then check other wire for same. If you read nothing the timer is bad. Then ohm out the heater and see if you have continuity below 100 ohms. The terminator will have to be below 32 degrees to test it, but will read zero when that cold. Plug the parts back together and see if refrigerator comes back on in about 15 minutes. If it does not then the timer is not advancing and the timer motor is bad. Replace timer if this is so. Check your fan and see if it comes back on, too. If possible, oil the motor by putting a little oil on rear shaft into felt pad at rear of motor. Also, check under unit and clean out dust and dirt twice a year. This should take care of everything. DrTom4444