Product review (5 stars): Got our washer back in business
The previous home owners didn't mention the washer had a problem with water pressure in the upper tray. I took it apart (I'm not a repair tech, but I can google and read manuals enough to get by) and found that the previous assembly had broken (the little plastic nub that holds the blade on). And because of that the screen was totally blocked with gunk and therefore there wasn't sufficient pressure for the upper tray.

Putting in this replacement part was easy and our washer went from being all "Ugh this sucks- the top is still dirty!" to functioning properly.