Yes if the evaporator is ice up it will cause the fridge to get warm.
To check the defrost cycle look in the fridge section behind the light shield.
There you will find the defrost timer but all your will see of it is two screws and a knob between them.
With the compressor running turn the knob until the compressor stops running.
You are now in the defrost cycle.
The cycle will last at least 20 minutes.
Check your tray and see if you are getting any water in it.
If you get water in the tray then you have a faulty defrost timer.
If after 20 minutes the fridge starts back up and the fridge has not defrosted you have a faulty defrost thermostat or defrost heater.
You would need a meter to check these.
Here is a link to your fridge model Tfx25jrbbww.
Here is your defrost timer.
Here is your defrost heater and thermostat.  |