Akai S1000 / S1100 samplers

hi.  i own several akai samplers, though none are s1000 or 1100 i hope this list is also for 
other similar s-series models (i have an s900, an s2800, an s3000XL and a CD3000).

a few years ago, my friend's CD3000XL stopped recognizing CDs, whether audio or data.  
it would just say "NO DISK".  about a year or 2 later, mine developed the same issue.

sometimes it seems this is triggered by not waiting for the unit to be totally ready and/or 
being a bit too fast with the CD-accessing buttons.  sometimes it seems like everything 
was fine, and then the next time it's turned on, it's not working.

the only thing that seems to temporarily "solve" the issue is unplugging the unit 
completely, SCSI, MIDI, and power, and leaving it like that for about 24 hours.  sometimes 
that doesn't work however and it takes longer.  sometimes i've even pulled it off its perch 
and opened it up, only to find that it would work again, sometimes not.  it's always 
eventually come back but it's frustrating being unexpectedly unable to work.

any suggestions what might be causing this, how to avoid it, and most importantly, what 
to do to make it come back?

someone on the midicase list suggested a dirty laser lens.  nothing looked particularly 
dirty in there, but i just got a can of air and blew it out.  tried a CD and...still NO DISK.

any leads would be much appreciated.


d.