Lots of ideas for no spin/drain on this unit, but since it works fine on the Delicate cycle, that seems to rule out a lot of things (e.g. lid switch, pulley, transmission, etc.) I did notice a post on another forum where someone had suggested the 2-speed motor in this unit might cause this behavior by working properly in slow speed but not high speed. I have swapped the motor with another one I had access to and determined it is NOT the problem.
I'm left thinking the problem is either in the timer or the control board mounted on the timer; since both of these are fairly expensive, I'd like to diagnose a little further to make sure which of these two (or something else) is the cause.