There are usually a few things that can cause this.
1. The controller sticks or has a defective terminal, Item 30 this link:
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5158184&diagram_id=893080#d893080
2. The termp control hangs intermittently Item F21 this link:
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5158184&diagram_id=887262#d887262
3. The run capacitor is intermittent. Item 55 this link:
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5158184&diagram_id=893080#d893080
I do not think at this time you have a run capacitor problem as the symptom repeats over the course of a year.
Here is the problem with me troubleshooting from the computer... I can not read voltages when the unit has defrosted itself to find out whether the controller or the temp control has failed. If you really want to isolate it.. you must leave it in the stuck in the defrosted condition and read voltages to find out which of the 2 has terminated compressor power.
Just one more thing to keep in mind... this unit does not have a defrost control so if there is a brief power outtage what can be happening is.. the coolant system pressures are too high to restart the compressor. It only takes a little over 15 minutes of off timer for the system to cool and stabilize. The next time it happens.. just unplug the freezer for a bit over 15 minutes and see if it restarts right away. If it does... then you had a power outtage that lasted for under 10 minutes.
Seeing a PF code or flashing clock on any other household appliance should be your in home NOTICE to go check the freezer to see if the compressor is running.
There are things like appliance start delay timer that you can puurchase but they are quite expensive. Making the decision to have an appliance start delay timer boils down to the question: Are the contents of the freezer worth the cost of the roughtly $150.00 timer?"
Just so you know there is one more digit afther the last W in the model number; that number being anywhere from a 0 to 9.
Thanks for choosing FixYa,
Kelly