I doubt it's alignment. They're pretty resiliant.
I might check cables, etc. If you were working in there, you may have jarred the ribbon cable loose, or possibly even damaged the ribbon cable. Make sure it's firmly plugged in on both ends. Check the power cable, while your at it.
Either of those is much more likely to give a "drive not ready" error.
Usually if a CD drive itself heads south, one of three things will happen. Either it won't spin up [bad motor], it won't spin down [bad laser/alignment], or it won't even be recognized [bad logic board].
