4 Jan
2005
4 Jan
'05
4:16 a.m.
At 05:46 PM 1/3/05 -0800, Dwight wrote:
If someone opened a disk and saw lube on the surface,
that disk had a failed bearing seal.
You know, that may be exactly what the problem is. The seal is failing
and the lube is coming out and gathering around the head and causing it to
stick the the platter. If the problem was due to lubricant on the platter
then the problem would occur even on relatively new disks. The fact that it
only seems to happen to old disk indicates that it's related to wear.
Joe
h>Dwight
From: "Brad Parker"
<brad(a)heeltoe.com>
"Joe R." wrote:
...
slide (or rotate) just as easily. I've looked
at a couple of drive platters
that had sticktion problems and there definitely seems to be wax or
something holding the heads to the platters.
I think almost all 3 1/2" drive media has some sort of coating on it.
What it is varies over time and mfg. I remember that most of it had
'lubrication like' properties - it's been a long time however and I may
be slightly off.
I seem to recall the magnetic coating was sputtered on and then another
coating was put on top. As I remember sometimes the top coating would
pool around the heads after they landed.
but it's all a dim memory and my memories are probably very dated these
days since the density has gone up by factor of 1000.
I do remember walking through Tony Lapine's labs and watching watching
drives running inside laminar flow hoods :-) head balistics where the
order of the day and made for some interesting firmware.
-brad