I cannot find info on your given model number.
Following is what comes up when I use your number.
http://www.appliancepartspros.c...earch.aspx?model=sxd25sw
See the models in the Matching Model Numbers section.
Please check the model number.

What you felt was the unit doing a defrost cycle.
This turns off the compressor, the condenser/compressor fan and the evaporator/freezer fan. It then turns on the defrost heater which is under the evaporator coils.


Defrost occurs about once every 8 hours of compressor on time. Defrost is usually a fixed time (30 minutes or so) but there is a thermostat clipped to the top of the evaporator coils. It opens just above freezing (frost has melted) and kills power to the heater for the remainder of the defrost cycle.
Perhaps it is not opening and therefore too much heat is being introduced into the freezer.

After defrost your fans and compressor should comeback on and cool down the unit.

From your description it sounds like the compressor does come back on but the unit does not get cold enough.
The freezer should be between 0 and 5 degrees F.
If not.
Is the compressor on. You can usually hear it but should also be able to feel it vibrating.
Is it cycling or on all the time other than when it is in a defrost cycle?
Is the condenser/compressor fan on?
Is the evaporator/freezer fan on?

Is the problem that the food thaws during defrost and then re-freezes?
It should not do this as defrost should not add much heat to the freezer compartment.

If the compressor is cycling then it could be that the main control thermostat is bad re: not measuring the temperature correctly.

Check your freezer temperature, should be 0 to 5 degrees F.

If higher and the compressor cycles, try a colder setting.
If that does nothing.
Unplug the unit.
Short the two thermostat wires together.
Make sure they cannot short to anything else.
Plug the unit in.
Compressor should come on and stay on unless the unit goes into defrost.
Chjeck your freezer temperature to see if it is getting colder.

[COLOR="Blue"]Too much information?[/COLOR]
Never can get too much info.

When the compressor runs the unit should cool down that is why knowing if it is on all the time is important. It will eventually hit a point that it cannot cool down anymore but this should be well below 0 degrees F.

Remove the cover in the freezer so you can inspect the evaporator coils.
Try to ensure that the compressor has run for at least an hour because if you do this shortly after or during a defrost cycle you could end up with the wrong diagnosis.

Three things can cause the compressor to run and not cool the unit down to the set point temperature.

1. Enough air is not being pulled through the evaporator coils to cool it properly.
Check that the evaporator fan is OK.
Check that the coils are not heavily iced/frosted over (plugged). If they are this points to a defrost problem.

2. A sealed system problem (low freon etc.).
If the coils have frost in one area (usually where the freon enters them), then it is a sealed system, problem.
This will be an expensive repair as you need a pro.
Often it makes more sense to put the dollars towards a new unit.
I would check the warranty on the unit as sometimes the sealed system has a longer warranty.
Below is a good site, take a look at the 3 example pictures about half way down the page.
http://www.applianceaid.com/ref...ator-not-cold-enough.php

3. This is the long shot as you would probably notice a large cold leak.
Check the door seals. If you have a very bad seal. If there is so much warm air getting into the unit that the compressor can not cool it down.