not sure how involved is this?
you would have to use a wet vac to remove all of the water, than remove the pump from the bottom of the unit, then check to see if there are any clogs. It can be fairly involved. Can you also double check the model number? That model is not coming up in my searches.
MVWB400VQ0 ? SER CY1970742 TYPE 580 NO WET VAC, SO PRETTY ROUGH
TIPPED IT BACK LOOKED PRETTY FAR OUT OF MY REACH SO I TIPPED IT FORWARD TO LOOK AT HOW THE BACK WAS SCREWED ON AND IT KICKED ON (SINCE I HAD IT PLUGGED IN_ BAD MISTAKE AND I KNOW BETTER-OR DUMB LUCK THAT IT STARTED- BUT, IT IS WORKING SO THANKS FOR THE HELP OR THE PUSH.