25 Jul
2011
25 Jul
'11
4:41 p.m.
Not the Apple one, but I have quite a bit of experience in working on the
Sony half-0height drive used in the HP9114B, later HP9123s, etc. It's
very similar mechanically.
The top head mechanism seems exceptionally fragile.
Yes, it is on most 3.5" drives, actually.
I went though a stack of drives where most of the
metal flexures have bent up so
the head no longer makes contact with the media. Sony doesn't seem to have done
a very good job of the mechanical design on this.
This normally happens when somebody pushes a paperclip in the ejsct hole
and doesn't push it in far enough. The disk ejects, but the mechansims
doesn't latch up. If you now pull the disk out, you wreck the upper head
mounting.
The full-height drives suffer from hardened grease o nthe ejcted mechansim
which casues this problem a lot. HP enthusisats know that one of old.
The half-height mechansim doesn't, but you need to make sure it's latched
befroe pulling the disk out.
-tony