I have looked at the CD repair FAQ (very informative!), and I have
done the following:

1. I have cleaned the lens with isopropyl alcohol.

2. I have discovered that the laser pickup WILL NOT re-center itself
under any condition if I manually move it away from the motor spindle.

3. As far as I can tell by simple observation, the laser pickup DOES
NOT light up under any condition. (I looked at the lens from an
oblique angle about 6 inches away from it in a darkened room.)

4. I have verified that the lens drive motor AND the CD spindle motor
do work OK. (I unplugged each motor's wiring harness and applied a
small DC voltage.)

5. I have cleaned the contacts on the little leaf switch that opens
and closes whenever the CD drawer opens and closes and verified that
the switch is opening and closing normally.

6. I have verified that all wiring harness connectors are clean and
well-seated.

Somehow, this player simply will not turn the CD playing circuits on
when the drawer closes. I think the logic IC is fried. Oh well, I
needed a few electronic parts, so now I have a whole box full!

Thanks to everyone for your help....