Break the law by being a daredevil? (Curiosity questions only.)

"Gordon Burditt" wrote in message
...
It is not ILLEGAL to open a PSU, at least not in the USA. But it is
UNWISE. The power capacitors inside store a lethal quantity of
electricity
in them long after the PSU is unplugged, and so you can kill yourself.
(I
suppose killing yourself could be viewed as illegal...)

Lethal? Maybe if you're wearing a ring and hanging onto a grounded point
with your other hand. Otherwise I have to disagree. The voltage may be
high
but the total energy is unliikely to kill you unless you work hard at it.

If you open up the power supply for a CRT-based monitor or TV, the
high voltages (can be over a thousand volts) on some pretty hefty
capacitors can kill you even if it's unplugged. You still might
need to be fairly stupid to get killed, like grounding yourself.
But I think it is possible and has happened numerous times that
someone can kill themselves by accident.

Over the past 45+ years I have replaced many dozens of TV picture tubes
i.e., CRTs, and have been zapped more than a couple of times (more in the
beginning, fewer in the mid-years and none in the latter stages : ) It
kicks like hell but far from killed me. I always removed my rings, etc. The
voltages IIRC are in the range of 15,000 volts but the amperage is quite
low. I wouldn't recommend that anybody mess around with such voltages but
I've yet to hear of anybody being killed although under extreme
circumstances I imagine one could -- ring on hand, bare feet in water, etc.
Think TASER gun; I suspect the voltages and amperages are on the same order.

Also the capacitors in a computer PSU are nowhere near the size of those in
TV high voltage supplies.




And yes, I've survived getting zapped, not only with it unplugged,
but with it plugged in and operating and sticking in probes to
measure voltages. In older TVs, the power supply is not a separate
part sealed in a metal box. The high voltages aren't all in the
power supply, either. Use *one* hand and don't ground yourself.
If you don't need it to have power while you are working on it,
unplug it and let it sit for a while. Watch what you touch. And
if you don't know what you are doing, don't try it.

If you open up the power supply for a computer (motherboard, not
CRT monitor), which typically outputs voltages like 5 and 12 volts,
you're a lot safer. The *input* voltages are higher, but since
they are AC, any capacitors on the input side won't have much stored
charge after you unplug them. With it plugged in, there will be
higher voltages present. It's not a real good idea to stick your
fingers in a light socket, either. You don't worry about touching
both ends of a battery when picking it up, do you? The voltages are
low enough to not present a danger.

Sticking your tongue on a 9-volt battery may be unpleasant, but it
won't kill you. Connecting myself to a 12V car battery via jumper
cables in the process of jump-starting another car doesn't even
tingle if you have dry hands. (Warning: the ignition system has
much higher voltages. Do not hold on to spark plug wires while
cranking the engine).

On Feb 15, 4:26 pm, "DaveW" wrote:
It is not ILLEGAL to open a PSU, at least not in the USA. But it is UNWISE.
The power capacitors inside store a lethal quantity of electricity in them
long after the PSU is unplugged, and so you can kill yourself. (I suppose
killing yourself could be viewed as illegal...)


Yeah, that's what I guessed, but I glanced over this, which was why I
asked:

http://groups.google.com/group/alt.c...c?dmode=source
" Working on high voltage equipment is always dangerous due to the
possibility
of fire and or electrocution. That's why its sealed with a warning and
that's why only those with the proper training should work on such
devices.
************* There's also a criminal and financial responsibility
involved. *************
So even if it doesn't seem like much the consequences can be
*tremendous*."

(emphases mine. Do the "tremendous" consequences include this alleged
"criminal" responsibility,
(not very tremendous compared to, well...) or are they referring to
the possibility of death (...that.)?)

Should've mentioned that in the post. Also, I heard that PSUs are
simply not meant to be
repaired, period, not even by a computer repair professional:

http://pcsupport.about.com/od/safety...afety_tips.htm

"Never Service the Non-Serviceable
When you come across labels that say "No serviceable components
inside" don't take it as a challenge.
Some parts of a computer are just not meant to be repaired,
********* even by most professional computer repair persons
********* .
You will usually see this warning on power supply units but you may
also see them on monitors, hard
drives, optical drives and other dangerous or highly sensitive
components."
(emphasis mine also.)

How accurate is any of this information I've been accruing?

(PS. I suppose the warning about hard drives only applies if you care
about the data on the drive, not,
for example, experimenting with an old junker that was acquired
specifically for that purpose.)

mike3 wrote:

There's also a criminal and financial responsibility involved.

This refers to what happens if you repair an ATX PSU for your
friend. Your friend goes home, plugs in the computer, and
goes to bed. Later in the night, the supply catches fire.

Much later, the fire marshall and the insurance company, want to know
who modified/played with the supply.

Your friend's mom decides to sue, to help get money to rebuild the
house or pay for medical treatments for your friend. She has to
do something, after all, because the insurance was cancelled.

Even if you do stuff to your own power supply, you still
might run the risk of invalidating a fire insurance claim,
if the insurance company investigates and decides a change
to the PSU caused the fire.

Anything in the computer which is less likely to
catch fire, and burn down your house, has a lesser
risk associated with it. (For example, changing
sticks of RAM.)

Note that getting advice from USENET, you're going to
get lots of goofy, slightly off answers. Respondents
don't really care what happens to you. Remember
that, before you reach for that screwdriver...

Paul

On Feb 15, 2:10*pm, mike3 wrote:
Hi.

Although I would not probably ever do this in reality at all due to
the danger, I'd be curious as to know what would happen if one opened
up a computer power supply unit. I've heard that one can get in
trouble with the law doing this (unless one has the proper
qualifications?). Is that right, and does this mean that even if I
didn't get zapped, and did this enough times (say 10 counts of illegal
opening of a power supply unit), I could spend the rest of my life in
prison (maximum security prisons, too???)? And furthermore, would just
1 count have _lifelong_ consequences, even if I made it through the
jail term? Are these worse or better than getting electrocuted?

Just curiosity questions: I wasn't really planning on doing something
dumb.

Ahhhhhhhhh...

...gottabeatrollgottabeatrollgottabeatroll...

Yes... It's Every Bit as ILLegal as Removing Tags From Pillows...

Naughtius "Do Not Remove Tag Under Penalty Of Law" Maximus

It is not ILLEGAL to open a PSU, at least not in the USA. But it is UNWISE.
The power capacitors inside store a lethal quantity of electricity in them
long after the PSU is unplugged, and so you can kill yourself. (I suppose
killing yourself could be viewed as illegal...)


Yeah, that's what I guessed, but I glanced over this, which was why I
asked:

http://groups.google.com/group/alt.c...c?dmode=source
" Working on high voltage equipment is always dangerous due to the
possibility
of fire and or electrocution. That's why its sealed with a warning and
that's why only those with the proper training should work on such
devices.
************* There's also a criminal and financial responsibility
involved. *************

If you represent yourself as qualified to fix something, and you
do it improperly for pay for someone else, and it catches fire or
electrocutes someone because of the incompetent job you did, there
may be financial or criminal responsibilities. If you screw yourself
in this manner, fewer people will be complaining. You may still
be in trouble if you burn down the apartment building you live in.
On the other hand, if you try to send it back to the manufacturer
for repair, package it up, and set it down on a range where you're
cooking lunch, then go look for some stamps, you have a bigger
chance of causing a fire.

The manufacturer's notice should put YOU on notice that if you kill
yourself trying to fix it, your heirs have no business suing them
for it.

So even if it doesn't seem like much the consequences can be
*tremendous*."

How much does an apartment building and all of its contents cost?
How about a few dozen dead former residents of said building?

(emphases mine. Do the "tremendous" consequences include this alleged
"criminal" responsibility,
(not very tremendous compared to, well...) or are they referring to
the possibility of death (...that.)?)

Should've mentioned that in the post. Also, I heard that PSUs are
simply not meant to be
repaired, period, not even by a computer repair professional:

If I buy a power supply, I can reintend it to whatever purpose I
want to, including smashing cockroaches with it, and the manufacturer
has no business trying to reintend it back to what *he* intended.
This does not mean, however, that when it does a poor job of smashing
cockroaches, that I can claim it was defective under the warranty.

http://pcsupport.about.com/od/safety...afety_tips.htm

"Never Service the Non-Serviceable
When you come across labels that say "No serviceable components
inside" don't take it as a challenge.
Some parts of a computer are just not meant to be repaired,
********* even by most professional computer repair persons
********* .

I have had a power brick for a laptop end up making arcing noises
when you plugged it in, and it quit working. Turned out to be a
couple of bad solder joints. I opened it up, fixed this, sealed
it up again with duct tape, and it's been working fine. It's now
safer than it was, because the arcing generated a lot of heat but
didn't suck enough power to blow a fuse, so it might possibly have
caused a fire.

On the other hand, I probably wouldn't have tried to identify the
main power transistors in the PSU and replace them, because it's
too much trouble, not guaranteed to fix the problem, costs a lot
in shipping of tiny parts, and without a schematic which is never
included these days, I don't know the specs needed for the replacement.

Manufacturers, of course, want me to buy a new one. Manufacturers
also want you to buy a new CD and CD player after you've listened
to a CD once, as that gets them more sales.

You will usually see this warning on power supply units but you may
also see them on monitors, hard
drives, optical drives and other dangerous or highly sensitive
components."
(emphasis mine also.)

Power supplies for CRT monitors have *very* high voltages in them
(and the monitor circuitry and CRT also do). (I'm not sure about
LCD or plasma displays.) Power supplies or anything else that you
plug directly into the wall have high voltages in them. These can
injure or kill people, or start fires. If you don't know what you
are doing, don't try to repair them.

And remember, crossing the street is dangerous, and can kill you
(I am sure there are plenty of documented cases), but there are
plenty of people who are going to claim they've survived crossing
the street. Don't let these people convince you that you CAN'T get
killed crossing the street. But being forced to cross the street
isn't a death sentence.

Hard drives and optical drives do not have dangerous voltages in
them. (unless it's an external drive that includes a power supply
that plugs into the wall. External drives that plug only into USB
ports don't have high voltages). YOU may have dangerous voltages
in YOU (static electricity) that are sufficient to zap the electronics
(but will only give you a mild shock from touching a doorknob), but
if they are already broken, and you're about to void the warranty
anyway, who cares? Also, dust and dirt contaminating a hard or
optical drive can cause a head crash or otherwise kill the drive
and your data. If you don't have a clean room and open up the hard
drive platter enclosure, don't expect it to work reliably again.
You might possibly get lucky. Data-recovery specialists may have
setups to do this properly, if you're desparate to get your data
back.

I don't know of any reason why it's unsafe to open up a dead (and
unplugged) hard drive, take out the platters, have something printed
on them, and hand them out to employees as awards for a job well
done. A former employer did exactly that. The employees then spent
some time joking around trying to identify the bad tracks with a
magnifying glass or the naked eye.

How accurate is any of this information I've been accruing?

(PS. I suppose the warning about hard drives only applies if you care
about the data on the drive, not,
for example, experimenting with an old junker that was acquired
specifically for that purpose.)

richard wrote:

In order for a capacitor to store 1 amp of power,

....one "amp" of power? That's a new one because power = volts x amps

that capacitor would have to be about five times the size of your computer. At the least.

Only if your computer is the size of a pea.

mike3 wrote:

http://groups.google.com/group/alt.c...c?dmode=source
" Working on high voltage equipment is always dangerous due to the
possibility
of fire and or electrocution. That's why its sealed with a warning and
that's why only those with the proper training should work on such
devices.
************* There's also a criminal and financial responsibility
involved. *************
So even if it doesn't seem like much the consequences can be
*tremendous*."

Check www.repairfaq.org for information about electronics repair and
safety. It's great.

The danger of shock isn't that bad if the PSU is unplugged from the AC
cord. High voltage capacitors can remain charged if the PSU has
failed, because the failure may have blown a component or copper
trace, removing any path to discharge the capacitors. But a normal
working PSU will discharge in 30 seconds or less due to its circuitry
loading down the high voltage capacitors, but even if that doesn't
happen, there are almost always bleeder resistors that will discharge
them in 30 minutes.

Never open a PSU unless it's unplugged from the AC.

Never touch anything inside a PSU without first measuring the voltage
on it because any exposed metal can be at high voltage, including the
heatsinks. I've measured 170V DC on PSU heatsinks. Discharge all
voltage to the case by connecting a wire or resistor between the case
and the device, being sure to make the first connection to the case.

Never plug a PSU to the AC unless its cover is securely installed
(tighten all screws). The cover provides protection against electric
shock and exploding capacitors.

Never plug a PSU into an AC outlet that isn't grounded or protected by
a GFCI, and don't assume that an outlet is grounded just because it
has 3-prong sockets because some people replace broken 2-prong sockets
with 3-prong ones, as they're easier to find. The only situation
where it's acceptable to use an ungrounded outlet is when it's
protected by a GFCI, but beware that GFCIs can go bad without any
indication (IOW press the GFCI's test button, and verify that the wall
outlet has no voltage.

Also, I heard that PSUs are simply not meant to be
repaired, period, not even by a computer repair professional:

http://pcsupport.about.com/od/safety...afety_tips.htm

It's just not economical to have a computer shop repair a PSU because
the typical minimum labor rate is $60-100,.or more than the cost of a
typical brand new PSU. Also the average person working in computer
repair doesn't know how to do many actual repairs and just replaces
whole assemblies (PSUs, motherboards, cards, etc.). But it's silly to
say PSUs aren't meant to be repaired because I've repaired several,
and I'm certainly no technician. In fact a PSU may be the easiest
computer device to fix because so many of its components are generic
and are soldered in conventionally, not surface mount soldered.

Typical PSU failures are from bad fans, shorted transistors or diodes,
bad solder connections, and rotted capacitors (almost always the low
voltage ones, but sometimes a high voltage one in the +5Vstandby
circuit). The power supply forum at www.badcaps.net has detailed
information about the latter and how to fix it.





"Never Service the Non-Serviceable
When you come across labels that say "No serviceable components
inside" don't take it as a challenge.
Some parts of a computer are just not meant to be repaired,
********* even by most professional computer repair persons
********* .
You will usually see this warning on power supply units but you may
also see them on monitors, hard
drives, optical drives and other dangerous or highly sensitive
components."
(emphasis mine also.)

How accurate is any of this information I've been accruing?

(PS. I suppose the warning about hard drives only applies if you care
about the data on the drive, not,
for example, experimenting with an old junker that was acquired
specifically for that purpose.)

On Feb 16, 7:42 pm, Paul wrote:
mike3 wrote:
There's also a criminal and financial responsibility involved.

This refers to what happens if you repair an ATX PSU for your
friend. Your friend goes home, plugs in the computer, and
goes to bed. Later in the night, the supply catches fire.

Much later, the fire marshall and the insurance company, want to know
who modified/played with the supply.

Your friend's mom decides to sue, to help get money to rebuild the
house or pay for medical treatments for your friend. She has to
do something, after all, because the insurance was cancelled.

Even if you do stuff to your own power supply, you still
might run the risk of invalidating a fire insurance claim,
if the insurance company investigates and decides a change
to the PSU caused the fire.


Ah. This makes more sense.

Anything in the computer which is less likely to
catch fire, and burn down your house, has a lesser
risk associated with it. (For example, changing
sticks of RAM.)

Note that getting advice from USENET, you're going to
get lots of goofy, slightly off answers. Respondents
don't really care what happens to you. Remember
that, before you reach for that screwdriver...


Well, I wasn't planning on messing around with a PSU
like that anyway: like I said, these are curiosity questions.
Furthermore do you know of a source other than USENET
that is more accurate and is affordable to someone who
has less than $15000/year income?

Paul

On Feb 16, 9:57 pm, (Gordon Burditt) wrote:
snip

Thank you for the good answer.

On Feb 15, 9:11 pm, richard wrote:
On Sat, 16 Feb 2008 01:32:07 -0000, (Gordon



Burditt) wrote:
It is not ILLEGAL to open a PSU, at least not in the USA. But it is
UNWISE. The power capacitors inside store a lethal quantity of electricity
in them long after the PSU is unplugged, and so you can kill yourself. (I
suppose killing yourself could be viewed as illegal...)

Lethal? Maybe if you're wearing a ring and hanging onto a grounded point
with your other hand. Otherwise I have to disagree. The voltage may be high
but the total energy is unliikely to kill you unless you work hard at it.

If you open up the power supply for a CRT-based monitor or TV, the
high voltages (can be over a thousand volts) on some pretty hefty
capacitors can kill you even if it's unplugged. You still might
need to be fairly stupid to get killed, like grounding yourself.
But I think it is possible and has happened numerous times that
someone can kill themselves by accident.

And yes, I've survived getting zapped, not only with it unplugged,
but with it plugged in and operating and sticking in probes to
measure voltages. In older TVs, the power supply is not a separate
part sealed in a metal box. The high voltages aren't all in the
power supply, either. Use *one* hand and don't ground yourself.
If you don't need it to have power while you are working on it,
unplug it and let it sit for a while. Watch what you touch. And
if you don't know what you are doing, don't try it.

Exactly. In my highschool electronics class, one of my friends
accidentally touched the coil of a crt, which was unplugged, and it
took about five minutes for the juice to drain through his body. He
was ok.





If you open up the power supply for a computer (motherboard, not
CRT monitor), which typically outputs voltages like 5 and 12 volts,
you're a lot safer. The *input* voltages are higher, but since
they are AC, any capacitors on the input side won't have much stored
charge after you unplug them. With it plugged in, there will be
higher voltages present. It's not a real good idea to stick your
fingers in a light socket, either. You don't worry about touching
both ends of a battery when picking it up, do you? The voltages are
low enough to not present a danger.

Sticking your tongue on a 9-volt battery may be unpleasant, but it
won't kill you. Connecting myself to a 12V car battery via jumper
cables in the process of jump-starting another car doesn't even
tingle if you have dry hands. (Warning: the ignition system has
much higher voltages. Do not hold on to spark plug wires while
cranking the engine).

Precisely. That's what the coil does. It increases the voltage to like
around 50,000 volts (5,000?) which makes the current less than a 1/10
of an amp. It's the voltage arcing across the spark plugs points that
ignite the fuel. Not the current.


How come a monitor has so much more juice in it than a desktop's
PSU? Is it because of that electron gun?