Thanks for all the suggestions.
I spent some time working on the player over the weekend and solved the problem!
I took the unit apart, removed the spindle clamp, removed the disc, checked the limit switches (there are 3 that I could find). I tried pressing them individually and in various combinations and nothing worked. Finally I figured I would try to simulate an end-of-disc situation...I rotated the pickup assembly into the top read configuration (side b read) and slid it into the center near the spindle. I then powered the unit. The pickup assembly sensed that it was not "home" and moved the assembly back and over. The spindle lowered and drawer opened...and now works great!
So, now I know what to do next time this happens!
If anyone ever encounters this situation, it might be a good "first try" to fix the problem. You must, however, be very cautious in being very gentle when you move the mechanism...it does appear to be fragile.