any suggestions,my freezer gets to minus 20.And my food/ milk area gets to 20 degreesF.I replaced the temp control thermostat and the freezer fan which had stopped working . When I turn off the temp control in the frigerator eventually the temp rises from 20f to 40f then the compressor will come back on. And it starts to freeze up again I turned the defrost timer by hand and the evap heater does come on and start melting