Have you tried cleaning the head on the disk drive?
Use a cotton swap
with isopropyl alcohol to clean it - I've seen them get pretty gunky.
Also, is the little felt pressure pad at the top present and accounted
At onme time that felt disk was avaialble as a spare part from Sony and
HP. Not any more, though...
for? If it's missing, the disk won't make
constant contact with the head
and you'll get random read errors. Also, double check to ensure the
rails the head rides on are clean and free of grease or gunk - they can
prevent the head from moving to further tracks.
Also cehck for hardened grease in the leandscrew on the stepper motor.
This can prvent the head from moving properly.
These drives are very well made. Provided you don't touch the stepper
motor fixing srews (and the track 0 sensor on a stnadard drive, I dont
thin kthe Appie drive has one), you can take everything else apart
(including removing the slide rain and the head carriage and it'll be
properly aligned when you put it back together. Heck, I once replaced the
head carriage on an HP-badged double sided drive with one from another dead
drive and when I put the alignment disk im, it was not spot-on, but it
was well witing toleraance.
-tony