Our GE Profile dishwasher won't fully drain. We end up with standing water just under the heating coil. I've found an older message on this forum about GE dishwashers, and tried removing the lower valve arm as was suggested in it. Even with the arm removed, it still doesn't fully drain.

What should I do next? I am a real novice in this, and I'm not even sure where the various things are that I should be checking.

Thanks for any help!