[SGVLUG] Calling the brightest of cal tech and other nerds!

[Don Gibbs]

I'd say it's an ESD (electrostatic discharge) issue.

Turns out, highly conductive surfaces are not a good thing when ESD 
sensitive parts are close by.  An ideal surface (from an ESD control 
perspective) is one which is only modestly conductive.  Such a 
surface effectively dissipates a static charge, but over a relatively 
long period.  A highly conductive surface will dissipate that same 
charge but as a surge.  It will, in effect, deliver a high power 
pulse (dV/dt or something).

A conventional metal case is not an electrically isolated Faraday 
cage (with one meter air gap).

I would think that the best way to handle ESD sensitive parts would 
be to put on a wrist strap which is grounded a common ground first, 
then touch the case, then handle the parts.  I could go on and on, 
but that would get boring.

Of course, it could be something else altogether.  :)

   --Don

>matt gallizzi and I, both frequent attendees of the cal tech lug 
>have the strangest problem ever, static electricity keeps shutting 
>down a computer we recently built, because its an all metal case. We 
>have verified every part 100% from switching ram to cpu to mobo, to 
>PSU, EVERYTHING, however we both still have this strange problem, 
>isnt the point of touching the metal part of a case supposed to 
>ground you from static discharge in the first place? obviously that 
>rule isnt applying here, any feedback is greatly appreciated !


-- 
========================================================================
Don Gibbs		| "Somehow it seems to fill my head with ideas
dgibbs at jpl.nasa.gov	| -- only I don't know exactly what they are!"
818 354-2990 - office	|
818 653-9531 - cell	|       Alice, after reading JABBERWOCKY

Sec 316, Flight S/W & Data Systems - Group B, GN&C and FSW Testing
Opinions expressed are not necessarily those of JPL/Caltech or NASA