My MSF-49NM freezer get hot and not cold when truned on; how do I resolve this.

SOURCE: msf-49nm evaportor pan and drain iced up

I deal with MasterBilt which is a private lable made by TurboAir.
I have several units but only one does this icing up thing. Look for a bad seal on the door gasket. These really ice up if that does not seal almost perfectly. Look for premature termination of the defrost cycle. Check that the heater is pulling amps. The wiring diagram at "turboairinc.com" is very poor but it shows 2 heaters for the refrigerator. They list a diagram for the freezer but it's not there. I know for sure that there is a heater for the evap but don't know about the drain. I've seen some have it and some don't. there tech support line has much to be desired but it's worth a shot. Also, the bottom hinge on the door fails fairly regularly. This allows the door to drop just enought to disengage the switch at the top of the door and stop the evap fan from running, thus causing a freeze up.
Good Luck . You got your hands full with this one.

SOURCE: msf-49nm freezer will not go

Change the temp control,check to see if it is iced up on the evaporator