Fills but doesn\\\'t wash

My dishwasher fills and that\\\'s it. The sprayer arms don\\\'t do anything and the water will not drain out. I ck\\\'d the filter inside the unit, it is clean. And there are no kinks in the drain hose. I can hear a humming noise, but no action. I just installed a new disposal and the knock-out plug is out.....what could it be? Thanks.

sounds like a ceased circulation pump to me

Thank you for responding!
I can hear a humming noise, and I can hear the dial ticking as it goes through the cycles, but that is all. So I need to call a professional to replace the pump?

If your dishwasher is humming, but not washing after it fills, you may have a stuck motor on the pump. A technician may have to remove the inspection panel and turn the motor by hand to free it up. This happens on Camco dishwasher brands after sitting for an extended period (not being used). There is seldom any other problem caused by this sticking.

My unit is a Whirlpool, about 4 yrs old.
I am able to get the bottom panel off and expose the parts. I am thinking if I shut off the eletricity, I might be able to unstick the motor or pump. Of course, I don't know what the motor and pump look like! Or should I leave this to a Professional?
Thank you for ANY help you can give me.

Oh, did I mention the DIRT smell that is coming from my NEW disposal? I preplaced the unit because of the smell, but it still stinks! I have run bleach through the D/W, and I have unhooked the drain line and cleaned it, I have cleaned out all the drain pipes under the sink (the D/W does NOT smell). Ironically, that's when the D/W stopped working (I have taken out the knock-out thingy in the disposal). Any suggestions?