23 Feb
2006
23 Feb
'06
11:45 a.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