Did low voltage cause the pc to fail?

"w_tom" wrote in message
...
In the real world, only those with a bean counter mentality
have power supplies damaged by brownouts. When a power supply
is damaged by a brownout, then the reason for failure is
directly traceable to a human who failed to learn basic
technology.

May I ask just how many years experience YOU have in
power supply, design, and construction in the commercial
world (i.e., actually shipping this sort of product in volume)?

Bob M.

Bob Myers wrote:
"w_tom" wrote in message
...
That's all good and nice reasoning which the designer
already considered when he designed a power supply that is not
damaged by brownouts.

Or so you hope.

One of the things I used to do (in a past life, but for my
current employer) was to supervise the environmental, etc.
qualification testing of new products. Do you think we
never EVER found problems with power supply design
that showed up in the AC line compatibility testing?

It would be a truly wonderful world in which everything
was designed as it should be, in which everything was
actually BUILT per those designs, and in which the
components that went into that construction never ever
had any sort of problem of their own. Just as soon as
you find that world, you let us know.

Your ignorance is really showing up. If the specs are not met, that supply
goes back on guarantee and it eventually will drive this supplyer out of
business. In Europe we have now a 2years guarantee by law and believe it or
not, when a part fails because of undervoltage the seller has to take it
back and repair/replace it.


Intel does not make power supplies? Underwriters Laboratory
- UL - does not make anything. Therefore UL standards don't
exist either?

Both Intel-generated specifications exist, and UL standards
exist. And so, according to you, everything ever
designed and built automatically complies with those
standards? Hallelujah! I can call down to the test lab
right now, and tell those guys to take it easy! There's
nothing more for them to do!!!!


It is a criminal offense if UL-specs are not met, and if any personal injury
happens you will pay big bucks. There is a responsability involved and if
you fake the CE or UL or whatever rules apply in your country, you will be
prosecuted.


If a computer power supply is damaged by the brownout, then
the brownout is not a reason for failure. That failure is
directly traceable to the human who typically buys on price
rather than first learn basic electricity concepts.

If the power supply does not come with written specs -
things they actually claim to do

First, it's hardly reasonable to expect anyone who buys
a power supply to be sufficiently educated in power
supply design so as to recognize a good design or a bad
one at first glance. (Hey, if they're THAT good, they should
be designing and building their OWN, and then I know several
places that will likely want to hire them!) Second - you again
show an awful lot of faith in the mere presence of "written
specs." Many aren't worth the paper they're printed on.


Mr Meyer, you must be one of those bean counters. What a stupid and arrogant
commentary. The consumer has a lot of laws on his side and especially in the
US you better not deliver any sub-spec mercendise declared as being ok. If
you buy at the surplus store or Ebay, you might end up with what you are
descibing, but this stuff is not guaranteed meeting the specs.


blame themselves. Brownouts do not damage properly
constructed power supplies...

...as long as they were properly designed AND
constructed, built from perfect components, and have
suffered absolutely no ill effects due to age, electrical
or mechanical stress, etc., since being built. By this same
sort of reasoning, I should be able to claim that NOTHING
which is "properly designed and built" should ever fail. Once
again, the reliability guys will be SO glad to hear that...


Bob M.

--
ciao Ban
Bordighera, Italy

Here in the US we have 240/120 supplied to homes. If the grounded conductor
fails, the voltage can divide up as 100 and 140 or as 80 and 160 and so on
depending on the loads at the time. Maybe that's what happened and it was
overvoltage that fried the computers.

"Ban" wrote in message
...
Your ignorance is really showing up. If the specs are not met, that supply
goes back on guarantee and it eventually will drive this supplyer out of
business. In Europe we have now a 2years guarantee by law and believe it
or
not, when a part fails because of undervoltage the seller has to take it
back and repair/replace it.

So if it fails within that 2 year period, great; do you believe
that all suplies which fail due to an undervolt condition are
within their warranty period? Or that simply because a
failure DOES occur within the warranty period, that this
MUST be indicative of a sufficiently widespread problem such
that the supplier WILL be "driven out of business?"

Again, if your model is correct, power supplies that don't meet
spec should never be found in the real world. I claim that
such things do, in fact, exist. Care to bet which of us can
support their position through evidence?

As to "my ignorance really showing" up, you're right - after
25+ years as an engineer working for one of the major
computer companies, I clearly don't know squat about the
realities of the electronics manufacturing business.

Both Intel-generated specifications exist, and UL standards
exist. And so, according to you, everything ever
designed and built automatically complies with those
standards? Hallelujah! I can call down to the test lab
right now, and tell those guys to take it easy! There's
nothing more for them to do!!!!


It is a criminal offense if UL-specs are not met, and if any personal
injury
happens you will pay big bucks.

Actually, it isn't, although that is a widespread misconception.
The UL standards do not carry the force of law, nor is there
any law making it a criminal offense to sell a product which is
not UL certified or registered. UL compliance can and will
enter into liability awards resulting from failed products, but
that is a civil issue, not a criminal one. Further, simply obtaining
UL certification basically just says that, IF built as designed
from the specified components, the product can reasonably be
expected to meet the specification in question. The nature
of testing and statistics being what it is, this can never be a
perfect assurance of 100% compliance, unless the product in
question is subjected to extensive finished-product testing
in 100% of the units shipped. Especially for consumer goods,
this is basically never the case, with the exception of a few
key specifications. And no testing can ever be a 100%
guarantee of continued compliance for all time, for the reasons
mentioned earlier having to do with aging, electrical and
mechanical stress, and so forth.

There is a responsability involved and if
you fake the CE or UL or whatever rules apply in your country, you will be
prosecuted.

Yes, but that's not what's being discussed here. Forging
a UL mark is irrelevant to the topic under consideration, which
is the reliability and failure modes of power supplies.


Mr Meyer, you must be one of those bean counters. What a stupid and
arrogant
commentary. The consumer has a lot of laws on his side and especially in
the
US you better not deliver any sub-spec mercendise declared as being ok. If
you buy at the surplus store or Ebay, you might end up with what you are
descibing, but this stuff is not guaranteed meeting the specs.

Nope; I am not now, nor have I ever been, a "bean counter."
It is simply a fact of life that NOT all products shipped will
meet their published specifications 100%, and those which do
will not continue to do so forever. Again, if you feel otherwise,
please call up the head of our service and support organization, and
inform them that everyone can go home now.

What published specifications really mean, from a legitimate supplier,
is that IF the product delivered does not meet the specifications
(which generally can be considered as being a part of the purchase
agreement - i.e., you did not agree to buy THIS product, but instead
you actually agreed to buy a product which met these specifications),
then you have the right to return it and expect a replacement. But
simply publishing the specifications by no means is perfect assurance
that every product shipped/received WILL actually meet its specs
when it reaches the customer. SOMETIMES, this is due to shoddy
design and/or manufacturing - but even the best manufacturer in the
world for whatever product you're considering still has the occasional
failure-upon-delivery. Welcome to the real world.

Bob M.

(Greg) wrote in message . com...
G'day from a long way away....

I am struggling with an argument about a couple of damaged home
computers and I was wondering if anyone can help????

The switchboard for a suburban house was replaced in November 2003.
Since February 03 various appliances in the house have failed,
including three pcs. The owners believe that lower than stat limits
voltage into the residence caused the failure. Since the switchboard
was replaced the problems have stopped.

Their electrician said that the switchboard was a 30 year old
porcelain-fused model and was burning out on the busbar and the
circuits on the board were overloaded with too many appliances.

My question to you, if you would be so kind...."What chance is there
that the slightly under supply of grid voltage would severely damage
pcs, or, is the pc damage more likely to be as a result of the arcing
at the switchboard?"

Greg,
Brisbane, Queensland, Australia

Hi Greg, I'm not going to take the time to read all of the answers you
have gotten. Remember what Abe Lincoln said, Beleive only half of what
you see and nothing of what you hear. My two cents is this: MOST
switching power supplies and probably all used in computers are rated
from 90 to 150 volts set to 120v and double that when set to 240. Our
engineers, way back in about 1985 built one that was to tolerate 90 to
300 without a switch to set the input voltage. It didn't make it, but
was great when the switch was added. Luck, Jim

X-No-Archive: Yes

(Greg) wrote in message . com...
G'day from a long way away....

I am struggling with an argument about a couple of damaged home
computers and I was wondering if anyone can help????

The switchboard for a suburban house was replaced in November 2003.
Since February 03 various appliances in the house have failed,
including three pcs. The owners believe that lower than stat limits
voltage into the residence caused the failure. Since the switchboard
was replaced the problems have stopped.

Their electrician said that the switchboard was a 30 year old
porcelain-fused model and was burning out on the busbar and the
circuits on the board were overloaded with too many appliances.

My question to you, if you would be so kind...."What chance is there
that the slightly under supply of grid voltage would severely damage
pcs, or, is the pc damage more likely to be as a result of the arcing
at the switchboard?"

Greg,
Brisbane, Queensland, Australia

Do you have the detailed description of failure? Poor quality power
supplies have a disgustingly low hold up time and even the best power
have a limited hold up time.

Hold up time is the amount of time the power supply can sustain proper
outputs when input power is lost. Usually, when power goes out or
browns out severely briefly but longer than the hold up time, the
computer will reboot suddenly. If it happens at just the right time,
it can corrupt the HDD. I've heard of power supplies that's so crappy
that computer reboots when UPS tranfers to battery, because it it
couldn't hold up during a ~5mS transfer time.

You may be interested in products by APE, they have a device that will shut
down the power supply if the voltage goes below a safe level. It sells from
memory for around $80. Available from radio parts
http://www.radioparts.com.au/ProdVie...oduct=12354978

Regards,
Stephen Lakey.
"Greg" wrote in message
om...
G'day from a long way away....

I am struggling with an argument about a couple of damaged home
computers and I was wondering if anyone can help????

The switchboard for a suburban house was replaced in November 2003.
Since February 03 various appliances in the house have failed,
including three pcs. The owners believe that lower than stat limits
voltage into the residence caused the failure. Since the switchboard
was replaced the problems have stopped.

Their electrician said that the switchboard was a 30 year old
porcelain-fused model and was burning out on the busbar and the
circuits on the board were overloaded with too many appliances.

My question to you, if you would be so kind...."What chance is there
that the slightly under supply of grid voltage would severely damage
pcs, or, is the pc damage more likely to be as a result of the arcing
at the switchboard?"

Greg,
Brisbane, Queensland, Australia

"w_tom" wrote in message
om...
Unervoltage - also known as a brownout - does not damage electronics.
Unfortunately too many take what they learned about motors and
expolate that to knowledge about electronics. One must first learn
basic concept before making assumptions such as low voltage will
damage a computer.



Undervoltage most certainly *can* damage electronics, some poorly designed
SMPS's will attempt to compensate for the low line voltage and blow
themselves up. Properly designed equipment won't do this, but there's a
great deal of poorly designed junk on the market these days.

"Bob Myers" wrote in message
...

"Ban" wrote in message
...
Your ignorance is really showing up. If the specs are not met, that
supply
goes back on guarantee and it eventually will drive this supplyer out of
business. In Europe we have now a 2years guarantee by law and believe it
or
not, when a part fails because of undervoltage the seller has to take it
back and repair/replace it.

So if it fails within that 2 year period, great; do you believe
that all suplies which fail due to an undervolt condition are
within their warranty period? Or that simply because a
failure DOES occur within the warranty period, that this
MUST be indicative of a sufficiently widespread problem such
that the supplier WILL be "driven out of business?"

Again, if your model is correct, power supplies that don't meet
spec should never be found in the real world. I claim that
such things do, in fact, exist. Care to bet which of us can
support their position through evidence?

As to "my ignorance really showing" up, you're right - after
25+ years as an engineer working for one of the major
computer companies, I clearly don't know squat about the
realities of the electronics manufacturing business.

Both Intel-generated specifications exist, and UL standards
exist. And so, according to you, everything ever
designed and built automatically complies with those
standards? Hallelujah! I can call down to the test lab
right now, and tell those guys to take it easy! There's
nothing more for them to do!!!!


It is a criminal offense if UL-specs are not met, and if any personal
injury
happens you will pay big bucks.

Actually, it isn't, although that is a widespread misconception.
The UL standards do not carry the force of law, nor is there
any law making it a criminal offense to sell a product which is
not UL certified or registered. UL compliance can and will
enter into liability awards resulting from failed products, but
that is a civil issue, not a criminal one. Further, simply obtaining
UL certification basically just says that, IF built as designed
from the specified components, the product can reasonably be
expected to meet the specification in question. The nature
of testing and statistics being what it is, this can never be a
perfect assurance of 100% compliance, unless the product in
question is subjected to extensive finished-product testing
in 100% of the units shipped. Especially for consumer goods,
this is basically never the case, with the exception of a few
key specifications. And no testing can ever be a 100%
guarantee of continued compliance for all time, for the reasons
mentioned earlier having to do with aging, electrical and
mechanical stress, and so forth.

There is a responsability involved and if
you fake the CE or UL or whatever rules apply in your country, you will
be
prosecuted.

Yes, but that's not what's being discussed here. Forging
a UL mark is irrelevant to the topic under consideration, which
is the reliability and failure modes of power supplies.


Mr Meyer, you must be one of those bean counters. What a stupid and
arrogant
commentary. The consumer has a lot of laws on his side and especially in
the
US you better not deliver any sub-spec mercendise declared as being ok.
If
you buy at the surplus store or Ebay, you might end up with what you are
descibing, but this stuff is not guaranteed meeting the specs.

Nope; I am not now, nor have I ever been, a "bean counter."
It is simply a fact of life that NOT all products shipped will
meet their published specifications 100%, and those which do
will not continue to do so forever. Again, if you feel otherwise,
please call up the head of our service and support organization, and
inform them that everyone can go home now.

What published specifications really mean, from a legitimate supplier,
is that IF the product delivered does not meet the specifications
(which generally can be considered as being a part of the purchase
agreement - i.e., you did not agree to buy THIS product, but instead
you actually agreed to buy a product which met these specifications),
then you have the right to return it and expect a replacement. But
simply publishing the specifications by no means is perfect assurance
that every product shipped/received WILL actually meet its specs
when it reaches the customer. SOMETIMES, this is due to shoddy
design and/or manufacturing - but even the best manufacturer in the
world for whatever product you're considering still has the occasional
failure-upon-delivery. Welcome to the real world.

Bob M.



I think anyone who actually works on real world products will quickly come
to this same conclusion. Like it or not, there's a lot of pure garbage that
ends up on store shelves. For every well designed piece of equipment I work
on, I come across at least half a dozen things that make me want to find the
engineer who designed it and smack them over the head with the thing.

"Bob Myers" wrote in message
...

"w_tom" wrote in message
...
In the real world, only those with a bean counter mentality
have power supplies damaged by brownouts. When a power supply
is damaged by a brownout, then the reason for failure is
directly traceable to a human who failed to learn basic
technology.

May I ask just how many years experience YOU have in
power supply, design, and construction in the commercial
world (i.e., actually shipping this sort of product in volume)?

Bob M.





Let's face it, the guy is a troll, spouting out all sorts of rubbish with
nothing to back it up. The crossposting doesn't do anything to support his
credibility either. It's a clear and proveable *fact* that some power
supplies will fail when run at low line voltage, he may wish to stick his
head in the sand and refuse to believe that such products are out there but
they do exist and I would guess that a great many of them somehow manage to
outlast their warranty period before failing, or fail due to other causes
first.