Re: replacing head assy in a hard drive

Ken <user@xxxxxxxxxxxxxx> writes:

> I agree with the other posters, but there is the freezer technique that
>I would try before giving up if there is data you wish to recover. I
>trust you know what I am referring to??? My guess is that it is the
>disk that is more likely to be your problem, rather than the heads. If
>that is true, your head swap effort would be for naught even if you were
>successful, and that is unlikely.

I would like to know why you think the disk is the problem. As I said, it
failed while transferring data, and never again did anything but click. Were
it a media defect at the particular location, it should still come online and
fail when accessing that area. Were it a defect in the firmware storage areas,
it should not have failed while running, but at bootup.

I think it's funny how everyone jumped on me for not being in class 100 clean
room. Unlike apparently everyone here, I have opened and run hard drives
both without the cover and with the cover replaced, and they do not instantly
crash. Yes, they probably do eventually crash (at least one did after several
days), but that's not what I'm worried about. The head to platter alignment
issue bothers me more, since there are 4 platters and I presume 8 heads (I
haven't opened this drive yet). Unless the heads are precisely aligned with
each other at manufacturing time ensuring that every set of heads is identical
(or at least identical enough for our purposes), a disk format with one set of
heads will be unreadable by another set due to differing physical displacement
between the heads.

.

Relevant Pages

  • Re: Why magnetic drums was/are worse than disks ?
    ... keep all heads on an arm assembly working ... Virtually no disk today has multiple heads per platter side. ... thermal expansion, bearing tolerances, etc. mean that only one head can be ...
    (comp.arch)
  • Re: Why magnetic drums was/are worse than disks ?
    ... disks ultimately displaced drums and that's ... heads as close together as disk tracks are (especially heads that can be ... platter and head count has to be worth something: ...
    (comp.arch)
  • Re: Why magnetic drums was/are worse than disks ?
    ... disks ultimately displaced drums and that's ... heads as close together as disk tracks are (especially heads that can be ... If that means a configuration of "drums" ...
    (comp.arch)
  • Re: hard drive park position
    ... Most modern hard drives now park their heads off the platters ... Ramp Load/Unload Technology in Hard Disk Drives: ... Earlier designs parked the heads on the outer edge of the platters. ...
    (alt.comp.hardware.pc-homebuilt)
  • RE: fixed drive name
    ... Disk /dev/sda: 73.4 GB, 73407488000 bytes ... 255 heads, 63 sectors/track, 8924 cylinders ...
    (RedHat)