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Major Appliances/Why are Microwave Cavity Light and Fan constantly running


I have a Kenmore Elite 600 CFM Reversible Door OTR Microwave made by Samsung. Model #592-857130 (Canada) or 40188522900 ? (US) (guessing at US Model # based on parts diagram found at
I have the following documentation that came with the unit, but they do not provide the information that I require to solve the problem.
Microwave Hood Combination: Use & Care guide (DE68-03653B-02)
Microwave Hood Combination: Installation Instructions (DE68-03654B-03)
Microwave Oven Tech Sheet (DE68-03683B-01)
I am looking for the detailed Service Manual and Schematics Diagrams to diagnose an issue with this microwave.  The issue I have is the Microwave Cavity Light and Fan are constantly running when the unit is plugged into the wall.  The hood fan & light work fine at varying speeds/intensity.  The clock works fine.  I have not left the unit plugged in or tried heating anything in it as I am unsure what the constant Light & Fan running means and if there is any impact to the unit if I use it in this condition.  I have attempted to test the various Fuses/Thermostats, etc as per the Tech Sheet, and they all appear to be fine, but I may be missing something.  
Any help you can provide would be greatly appreciated.


I would be looking at one of the door interlock switches or a relay on the control board...depending on the wiring diagram and how they are turned on.  Either a micro switch or a relay on the control is shorted or damaged since the unit is new....You seem capable so check these two items.  Let em know what you find for my benefit.  Thanks

Waiting to hear from you,
Eric and Ann Campion

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Eric Campion


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