DANGER! 17,000 VOLTS!

From: Charles E. Fox <foxvideo_at_wincom.net>
Date: Thu Jun 4 09:32:57 1998

At 06:39 PM 6/3/98 -0400, you wrote:
>
><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
>
>
        This is sort of off topic, but also sort of funny so please forgive me.
Many years back, when I was doing tv repairs, I had a St Bernard. One humid
summer afternoon while trying to repair a set I poked my insulated
screwdriver into the high voltage supply. Nothing happened except the hair
on my arm stood up. I pulled out the screwdriver and the hair went back
down. I poked the screwdriver back in and the hair went back up. About then
the St Bernard came up to be sociable and a spark jumped about three
quarters of an inch from my arm and hit him in the nose. He was not amused
and would not come near me until his appetite got the better of his
feelings at supper time.

                                                        Regards
                                                        Charlie Fox
Received on Thu Jun 04 1998 - 09:32:57 BST