DANGER! 17,000 VOLTS!

From: Allison J Parent <allisonp_at_world.std.com>
Date: Wed Jun 3 17:39:01 1998

<I have wanted to ask this for a while. What is the actual risk of me
<blowing myself up if I service a machine with a built-in monitor?
<An example is the Mac SE. Is there any risk involved (as long as I
<don't short capacitors with my fingers) in taking it apart? What are

if your careful and aquaint yourself with where the HV is...and make
very sure you don't put your fingers there you should be ok. Also
remember that 17,000 volts can jump a good distance and find you
fingers.

To make a point though... I got blasted fixing a VR201 monochrome monitor
yesterday. So you know this monitor is powered off 12v in the pro350.
Well, I kept clear of the flyback and crt anode and got nailed by 70-100v
down on the logic board. I wasn't watching for the focus cap having
anything big voltage wise on it. Many monitors have points other than
the CRT where higher than supply voltaged can be found and some can really
sting!

<the parts I should watch out for? How long do they hold a charge?
<Could I discharge them?

How long... amazingly long and should be treated as charged until proven
otherwise. You can discharge them, make sure the "ground" you use is
a real one and simply not the case or some other floating point.


Allison
Received on Wed Jun 03 1998 - 17:39:01 BST

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