Amana Masterclean 6000 won't drain

[UncleAtom]

I've got an Amana Masterclean 6000 which will no longer drain. It fills and cycles through cleaning phases, but won't drain. A plumber said it's not a plumbing problem. I haven't removed it yet, but would appreciate any pointers or tips on what to look for. Pump? Motor?

Thanks
Uncle Atom

 

[appnut]

If this is what I htinnk it is, it's  a model produced by GE.  I'm wondering if the drain valve solenoid is not working. 

 

[UncleAtom]

I'm a real newby with dishwashers - I guess I need to remove it first?