Maker Pro
Maker Pro

Did low voltage cause the pc to fail?

G

Greg

Jan 1, 1970
0
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
 
M

Michael A. Covington

Jan 1, 1970
0
We would need to know the nature of the PC failure. The only component of
the PC that could possibly fail due to a mains power problem is the power
supply, because its output is regulated -- it either outputs the right
voltages at full current, or shuts itself off completely.

It might over-exert itself stepping up a lower-than-normal input voltage...

Also, power cutting on and off repeatedly (a lot of "flickering") might
damage the power supply or even, I suppose, a disk drive or something. Did
that happen?
 
J

James Sweet

Jan 1, 1970
0
Greg said:
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


Either undervoltage or arcing can damage equipment.
 
W

w_tom

Jan 1, 1970
0
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.

The Intel specs are quite bluntly clear about this. AC mains
voltage can drop so low that incandescent bulbs are at less than 40%
intensity. Even at that low voltage, a computer with a full load of
peripherals must power up and run normally. Where is the damage? It
only exists in a world where people don't learn simple technologies
nor read manufacturer numerical specs.

What is a shutdown? Power is removed. Electrolytic capacitors
slowly discharge. The computer suffers a brownout - diminished
voltage. So the computer is damaged? Of course not. Computer must
work just fine until voltage becomes too low - and then it must switch
to a no more output mode. IOW a shutdown is a brownout that
eventually becomes a blackout. But if brownouts - low voltage - cause
hardware damage, then a shutdown will also damage hardware.

Can computers be damaged by a brownout? Well if it is, then the
computer fails to mean numerous industry standards and defacto
standards that have exists longer than most every reader here. The
answer to the OPs question is found in those specs. If undervoltage
damages the electronics, then the human knows exactly what the reason
for failure was - the human.
 
M

Michael A. Covington

Jan 1, 1970
0
w_tom said:
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.

The Intel specs are quite bluntly clear about this. AC mains
voltage can drop so low that incandescent bulbs are at less than 40%
intensity. Even at that low voltage, a computer with a full load of
peripherals must power up and run normally. Where is the damage? It
only exists in a world where people don't learn simple technologies
nor read manufacturer numerical specs.

Intel doesn't make PC power supplies. Sometimes we don't know *who* makes
them. I wouldn't put it past them to have something that would fail (or at
least blow a fuse) when subjected to undervoltage.

After all, undervoltage requires the switching power supply to draw *more*
current (as it gets less voltage).
 
S

Sam Goldwasser

Jan 1, 1970
0
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.

In an ideal world this would be so.

In the real World, it's quite possible that brownouts can cause
switchmode power supplies to fail.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header is ignored.
To contact me, please use the feedback form on the S.E.R FAQ Web sites.
 
W

w_tom

Jan 1, 1970
0
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.

Again - what is a power down or shutdown? A brownout that
eventually becomes a blackout. If brownouts damage
electronics, then so does turning the power off. This alone
is a damning fact. Brownouts do not damage properly
constructed electronics. Shutdown also does not damage those
electronics.

Even in those cited links, I find no reference to brownouts
causing electronics damage. The CBEMA specifically states
that all equipment must not be damaged by low volts. They and
other industry standards - including the computer industry
standard originally created by Intel - are quite blunt about
this. Brownouts don't cause electronics damage. Stated
bluntly even in specs.

Intel defines how computer power supplies must operate.
IBM, Dell, AMD, and a long list of other responsible
manufacturers also demand same standards be met. But this is
old technology - older than most lurkers have even existed.
However many bean counters buy 'dumped into North America'
power supplies to cut costs. Power supplies that violate
basic Intel requirements. Then those silly bean counter
mentalities try to blame others; then claim brownouts damage
electronics. Where is the logic in that? Its called
corruption.

Numerous industry standards for ATX power supplies were the
same defacto standards of 30+ years ago. Such defective
supplies are not found in brand name computers. Dumping only
works at great profit to the Asian manufacturer when a
computer assembler does not even have basic electrical
knowledge - buys power supplies on price rather than upon
technical specifications.

If anyone says that a brownout can damage properly designed
electronics, then we have a benchmark for a bean counter
mentality masking as technically knowledgeable.

Those who think otherwise are then invited to explain how
the individual components inside the power supply fail due to
brownout. That's right. I design at the component level -
not just rack and stack black boxes like a computer assembler
who need not have any electrical knowledge. Please feel free
to describe how that electrolytic capacitor or power
transistor is damaged by a brownout. One must be that
knowledgeable to foolishly claim brownouts damage electronics.
 
W

w_tom

Jan 1, 1970
0
That's all good and nice reasoning which the designer
already considered when he designed a power supply that is not
damaged by brownouts. There is even a circuit inside the
supply that cuts off power IF the supply cannot maintain
required output voltages. Same circuit also sends a signal to
motherboard. Again, no damage to hardware.

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

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 - then one should assume the
worst. These same 'discount' power supplies are sold to
computer assemblers who would blame the brownout rather than
blame themselves. Brownouts do not damage properly
constructed power supplies. Unfortunately those supplies cost
more money. Bean counter mentalities fear spending money.

I bought my power supply from some guy wearing a black
trench coat and it failed? That proves brownouts cause
computer damage? Unfortunately too many computer assemblers
who don't even have basic electrical knowledge use that
reasoning. A power supplies damaged by a brownout was
defective the minute it was purchased.
 
B

Bob Myers

Jan 1, 1970
0
The Intel specs are quite bluntly clear about this.

And, of course, every PC ever produced anywhere in the world
IS by definition completely, utterly, and totally compliant with
Intel's specs, right? :) :) :)

Ah, to live in such a world....


Bob M.
 
B

Bob Myers

Jan 1, 1970
0
w_tom said:
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.
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!!!!
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.

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.
 
B

Bob Myers

Jan 1, 1970
0
w_tom said:
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.
 
B

Ban

Jan 1, 1970
0
Bob said:
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.
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.

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.
 
C

Charles Schuler

Jan 1, 1970
0
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.
 
B

Bob Myers

Jan 1, 1970
0
Ban said:
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.
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.
 
D

dude

Jan 1, 1970
0
Isn't the question whether the PC failed or not?

I wouldn't consider the power supply the PC itself. I guess you could argue
that point but the power supply is a part that is made to fail, if
necessary, to prevent further internal damage to the PC. I've replaced many
power supplies on PCs that were struck by lightning (not directly, I'm
sure), the power supply was fried but the PC itself was fine after a new
supply was installed.
 
J

Jim Phelps

Jan 1, 1970
0
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
 
D

~Dude17~

Jan 1, 1970
0
X-No-Archive: Yes

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.
 
J

James Sweet

Jan 1, 1970
0
w_tom said:
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.
 
J

James Sweet

Jan 1, 1970
0
Bob Myers said:
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.


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.


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.



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.
 
Top