Sparks when starting then goes to pause mode - Kenmore Microwave Ovens

The key pad module is faulty.
If you wish to get some details; check the site linked here. Pull up older posts.
http://electro-medical.blogspot.com/

I have a hunch the microwave panel is going into Child lock mode and preventing you from operating the clear/off function. Not sure which is the middle switch that you replaced. I would suggest you give the panel a good wipe with a clean damp cloth to remove all grime etc. Before selecting the start/pause button press the Clear/off button for 3 secs and see if the L (lock) shows up on the display. Next press again for 3 secs to see if L goes away.

This way you have confirmed the panel is not in lock mode before you start next operation. Provide your observations in the comments section so that I can assess what the next step should be.

http://www.partselect.com/Models/KCMS185JSS3/ try this place
home micros don't have diag mode,, go or no go...

Pressing the Clear/Pause button works. Sometimes. Most of the time, about a microsecond after pressing Clear/Pause, it goes right back to def1. Most of the time, pressing ANY button doesn't work. Usually takes me 10 to 20 tries to get anything to work. My microwave is about 3 months old. I will never buy Emerson again.

Remove power for a while and after the power is switched back press and hold stop/pause.

see this steps and fix it. God bless you
If you see arcing or sparking inside a microwave, turn unit off immediately. Arcing can be caused by having something metal in the oven cavity touching a side, an oven shelf is touching the side of the cavity, an oven shelf support has broken, microwave waveguide, or bad magnetron.
If your microwave has a shelf in it, and you do not use it, keep it out. If one of the shelf supports breaks or comes out, the microwave will arc where the support was. You will have to sand the spot down, paint with appliance paint and re-install support. If the shelf shifts on the support and touches the side it will arc.
Your magnetron waveguide will either come out of the top, or side of the oven cavity. Some will have a stirrer in it(mostly top waveguides) with a panel over, or just a cardboard type cover over it. Over time, the stirrer cover can become warped from the heat which will expose the stirrer's metal shaft which will then cause sparking. These covers and stirrers come in a kit and can be replaced from inside the oven cavity.
Your cover over a side waveguide is coated with a substance on it, and overtime this coating can come off from the heat and moisture in the microwave. These waveguide covers are very easy to replace from inside the oven cavity. Touch up any paint that may have chipped or come off because of the arcing.
If your waveguide cover and/or stirrer are all OK, then the spark is coming from your magnetron. The antenna on your magnetrom has overheated and burned, sending the microwaves out at the wrong angle. If you catch this microwave oven repair early enough, you can usually get by with just replacing the magnetron. If the arcing has caused servere damage inside the waveguide, you will need a new microwave. Waveguides are not replaceable and most you can barely see into them, let alone sand and re-paint. In this case of microwave oven repair, when you remove the magnetron, you will see the burned antenna, or your magnetron will fail the test below.

see the guide for test the magenetron and another component.

That's the "Auto Weight Defrost" mode. Press the Clear/Pause button to get out.
Here's a link to the manual http://www.emersonradio.com/owners/MWO%20manual/MW8106W.pdf

Sounds like you have a faulty control panel. I would use a meter and test the power from the control board to the magnetron and circuit board. Chances are the control panel is faulty

Tech needed....problably needs new magnatron, diode or HVTransformer. Unplug and try to resatart before calling tech... check prices of repair parts on this site as they are cheaper than the cerified techs company parts.

Unless the control electronics fail, leaving the oven paused won't hurt anything but it will enable someone unfamiliar with to restart it with nothing in the cavity and this can damage the magnetron. Unless you are just checking the food for progress, I wouldn't recommend leaving it paused and 'armed.'