8 Dec
2006
8 Dec
'06
1:52 p.m.
Marvin Johnston wrote:
<snip>
Has anyone seen stiction on the IDE or later drives? The only stiction I've seen
has always been on the 5 1/4" MFM/RLL type drives, and probably ESDI/SCSI/SASI
as well although my experience is limited on those drives.
I had three cases out of it on ST-225 and relatives.
Something else I've noticed is that if a drive has
stiction, that stiction will
return after the drive sets for a while again. Anyone know what actually causes
stiction?
In the case of the ST-225 they used defective magnetic lubricant on the
axis which eventually
developed too much friction for the start up pulses in the motor to
overcome. A bit of a kick
as you mentioned is the only thing to try. once the disk stack is in
motion, the motors have to
be able to keep it going and if the friction is that great there is no
way that taking it apart will
fix anything.
Never saw it in the smaller drives, but I did see a number of them with
being unable to regulate their
speed, which may have been a vaiant. They would make different sounds
after startup and
eventually spin down when they could not find a place to track.
This could have been a failure to spin at the right speed, or a failure
to correctly lock
onto the reference servo and see a basic clock, or an increased friction
keeping it from
getting up to the correct speed.
Jim