Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!APLPY.JHUAPL.EDU!levene
From: levene@APLPY.JHUAPL.EDU (Robert A. Levene)
Newsgroups: sci.electronics
Subject: Static and crashing PC's
Message-ID: <9102041615.AA04354@aplpy.jhuapl.edu>
Date: 4 Feb 91 16:15:41 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: levene@aplcomm.jhuapl.edu (Robert A. Levene)
Distribution: usa
Organization: Johns Hopkins University Applied Physics Lab
Lines: 43

Here's the story:

I have a formica computer table with metal legs.  I also have a standard
office chair with metal legs atop plastic casters.

Just by sitting in my chair I generate enough static electricity to cause a
spark when I touch ground.  The chair also gets charged up, and when the
chair leg gets close to the table leg, a spark is generated.

My '83 TI Professional Computer (an MS-DOS machine) immediately crashes, as
indicated by the immediate blanking of the screen.  A Vulcan-neck-pinch
(ctrl-alt-del) is necessary to re-start the machine.  Both the TI Pro
and the Macintosh on the table are connected to an ISOBAR surge protector.
(The Macintosh SE is unaffected.)

My troubleshooting included:

 (1) checked the office ground

     - It is intact.

 (2) disconnected all extraneous connections, leaving only the Keyboard
     and the video plugged in

     - The system wouldn't crash without the keyboard plugged in

 (3) swapped keyboards

     - The systems crashed on the second or third spark


Anyone out there have any ideas apart from "Reduce your static?"  Perhaps
the spark generates enough EMP to crash the TI-Pro video board?

Please e-mail and I'll summarize the results if there's enough interest.

- R

-- 
Robert A. Levene     Internet: levene@aplcomm.jhuapl.edu   Bitnet: RXL1@APLVM

Disclaimer: I speak neither for my race, my culture, my country, my religion,
            my political party, nor my employer, but for me alone.