Whirlpool microwave open/close door

Hello all,
My Whirlpool Microwave (Model WMH73521cs-3) is about 1.5 years old and all of a sudden the display shows “Open/Close door” and won’t start and the inside microwave light does not turn on when the door is open.
Tried slamming door couple times, already did reset but doesn’t help.
It just won’t start when we add times and start or simply just press start.

other functions on the control panel works fine, exhaust fan and light also woks fine.

Obviously its out of warranty and whirlpool wants to charge $100 for diagnose and then parts/labor for repairs afterwards.

Anyone for suggestions…

Thank You
Jig

I’d say one of the door switches has gone bad.

I’m not sure which one, I’d need the wiring diagram.

http://www.appliancepartspros.com/whirlpool-switch-w10727360-ap5950105.html

http://www.appliancepartspros.com/whirlpool-switch-w10269458-ap4429884.html

http://www.appliancepartspros.com/whirlpool-switch-w10211974-ap4358023.html

http://www.appliancepartspros.com/door-parts-parts-for-whirlpool-wmh73521cs3.html