22 Feb
2006
22 Feb
'06
10:04 p.m.
Interesting FYI ... Like anyone who has been around the early days of
micro HDs, I have heard HDs make an attention getting squeal. After a
while, we knew/found out that it was caused by the grounding spring on
the bottom of the drive, and bend it out of the way. In glancing through
some old Compaq Service Bulletins, I saw IN PRINT that the fix was to
remove the grounding strap with the comment that the drive is adequately
grounded though other contact points.
22 Feb
22 Feb
11:16 p.m.
On 2/22/2006 at 7:04 PM Marvin Johnston wrote:
Interesting FYI ... Like anyone who has been around the
early days of
micro HDs, I have heard HDs make an attention getting squeal.
There's another type of squeal on older 5.25" drives. Some (Rodime, maybe)
used a spindle brake where a solenoid is attached to a friction pad
normally pressed against the spindle. I've had one or two drives where the
solenoid or its driving circuitry didn't work and there was a terrible
squeal as the friction pad worked against the spindle.
I simply removed the solenoid and allowed sufficient time for the unit to
spin down normally before moving the unit.
Cheers,
Chuck
23 Feb
23 Feb
10:08 a.m.
On Wednesday 22 February 2006 10:04 pm, Marvin Johnston wrote:
Interesting FYI ... Like anyone who has been around
the early days of
micro HDs, I have heard HDs make an attention getting squeal. After a
while, we knew/found out that it was caused by the grounding spring on
the bottom of the drive, and bend it out of the way. In glancing through
some old Compaq Service Bulletins, I saw IN PRINT that the fix was to
remove the grounding strap with the comment that the drive is adequately
grounded though other contact points.
I've been doing that since, oh, 1985 or thereabouts.
Uneven wear on the graphite button on the grounding strap is usually the cause
of the noise...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
2:45 p.m.
Interesting FYI ... Like anyone who has been around the early days of
micro HDs, I have heard HDs make an attention getting squeal. After a
while, we knew/found out that it was caused by the grounding spring on
the bottom of the drive, and bend it out of the way. In glancing through
some old Compaq Service Bulletins, I saw IN PRINT that the fix was to
remove the grounding strap with the comment that the drive is adequately
grounded though other contact points.
Is it, though? The spring is not to ground the whole drive, it's to
ground the spindle/disks. Apparently, static buildyp on the disks can
cause read errors (it induces small signals in the read heads), and the
bearings may not be that good a conductor due to the lubricant forming an
insulating film.
Certainly just about all hard drives (including the demountable ones on
my '11s) have grounding contacts. You would therefroe think they
performed some useful purpose.
-tony
6729
days inactive
6729
days old
3 comments
4 participants
participants (4)
-
ard＠p850ug1.demon.co.uk -
cclist＠sydex.com -
marvin＠rain.org -
rtellason＠blazenet.net