the dishwasher, model DMR77LHS, creates a loud grinding sound each time it goes into a draining cycle. Sounds like glass being ground up, but no visible evidence. I assumed the sound would go away after a few complete washing cycles. The dishes to be washed are pre-washed/rinsed. Are there directions and visuals to take the bottom screen out for cleaning, if needed. Or, should this be addressed by a Pro?