Thanks for the suggestions! Here are my findings:
Start by cleaning the lens
That was the very first thing I did, before I even opened the case or anything. No effect.
Next check the cables to the laser
Good idea; cables look ok though, all connected, no obvious issues.
Laser sled should move to spindle then lens should light and bob
So here is what happens with the way I have things adjusted right now:
1) I put the disc on the spindle, magnet on top of it
2) I hit the "Run" button on the controller
3) The cd spins gently. As it does so, the laser sled moves to the spindle and the lens bobs up and down, making a "click" sound as it does so
4) The cd starts to spin more quickly until it's going at a fair clip
5) The cd continues to spin, and spin, and spin, for a good, full ten seconds or so. The laser doesn't appear to be doing anything during this time period-- or at least, the sled isn't moving or anything
6) Finally, the lens bobs up and down again-- "Click!"--, the cd spins down completely, and the screen says "Please check disc!"
The original PSU puts out 1A so that's not the issue.
Cool, so I'm on the right path with the power. Only thing that occurred to me was that maybe the
actual output from either my wall socket or the Radio Shack power supply was less than 1 amp... one other thread on this forum had a guy with a problem like mine, and it worked in someone else's house but not his own. I doubt this is my problem, but I haven't abandoned the theory either.