[comp.sys.mac.misc] Fixing Old Mac Disk Drive

mmm@cup.portal.com (Mark Robert Thorson) (01/28/91)

Today I finally managed to fix my disk drive after about a dozen
unsuccessful attempts.  The problem started about a month ago,
during a spell of cold weather.  My Mac is in an unheated room,
and apparently it was cold enough that the drive wouldn't work
properly.

Something hard was preventing disks from being inserted more
than halfway in.  I forced a disk in, which was the wrong thing
to do, because that broke the disk drive in some fashion.

I talked to someone at CJS systems, who gave me some tips on opening
up the disk drive:  1) to unhitch the two side-springs, only unhitch the
lower end;  slip your thumbnail under the hook end of the spring and
lift it off the post 2)  remove the black plastic clip which loads
and unloads the heads;  if you don't do this, you'll bend the top head
too much when you take the top plate off the drive, ruining the
copper flexure spring.

After much trial-and-error including much disassembly and reassembly of
the drive and lubrication of sliding surfaces, I finally seem to have
fixed it.  There's a post on a lever on the top plate which ejects the
disc--I had bent this lever.  I had also splayed the sides of the
sliding lower plate.  By bending both back to something approximating
their original shape, I seem to have fixed it.