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The only thing thats really feasible is a visual inspectionIs there anybody out there that can provide me with
some advice on the testing of computer equipment
for traces of lightning damage/ power surge damage?
The short story is that there is no rigorous definitive testing feasible.We test computers for the insurance industry when a
claimant makes a claim regarding "lightning damage/ power
surge damage" to computers and computer peripherals.
The thing is people love to claim power surge damage when their PC failsBlankIs there anybody out there that can provide me with some advice on =
the testing of computer equipment for traces of lightning damage/ power =
surge damage? We test computers for the insurance industry when a =
In news:bnbfqr$mhe$1@ctb-nnrp2.saix.net,
ForensicOke <myforensic@hotmail.com> wrote these words:
| BlankIs there anybody out there that can provide me with some advice
| on the testing of computer equipment for traces of lightning damage/
| power surge damage? We test computers for the insurance industry when
| a claimant makes a claim regarding "lightning damage/ power surge
| damage" to computers and computer peripherals.
In about fifteen years of computer servicing I have only come across a
handfull of lightning damaged computers, and of those several have
exhibited very clear signs of damage. One was quite spectacular with a
hole burned into an internal modem where several components just
disintegrated, and another showed signs of damage around the serial port
on the motherboard. In a couple of other cases I have been able to see
no clear signs of any damage, and could only rely on anecdotal evidence.
(For example, the day after a severe thunderstorm someone brings in a
computer which stopped working during the storm.) Thorough examination
of the motherboard may show signs of damage to some of the circuit on
the underside of the board, or there may be no damage evident at all.
I have only once been asked to give an insurance statement regarding
lightning damage to an external modem, and was quite happy to do so, as
my own external modem had been damaged the same day during a storm.
(Incidentally, that was the only time I have had such damage to my own
computers.)
Power surges may cause similar damage, but more often than not I have
found any damage to be in the power supply - I can not recall any case
where there has been motherboard damage which could be attributed to a
power surge.
Obviously my experiences may be different to others. I live in an area
which is not particularly lightning prone, and which has a relatively
stable power supply, so I can only suggest you rely on gut feeling in
the absence of any hard evidence of damage.
--
Cheers
Oldus Fartus
Furthermore, I would like to know if there is a way to differentiate
between
a power surge not caused by lightning and a spike caused by lightning by
testing the components on the motherboard?
"ForensicOke" <myforensic@hotmail.com
Furthermore, I would like to know if there is a way to differentiate
between
a power surge not caused by lightning and a spike caused by lightning by
testing the components on the motherboard?
** IMO "power surge" = lightning induced voltage spike on the AC
suppy - including the earth wire.
Lightning surge = lightning induced voltage spike on any other
thing ( eg phone cables, antennae ... )
........... Phil
Hi Phil!
Thanks a lot for the quick response!
The whole question surrounding definitions is also an interesting and
sometimes confusing matter. The way you put it was our understanding as
well. Then the insurance industry (our clients) start complaining because
in
the insurance policies they deal differently with power surge and
lightning
surge. For e.g. the excess fees that the insured has to pay differs, some
insurance companies here do not even pay out when the claim is stipulated
as
damage via power surge, some companies here only pay for power surges when
it is a commercial claim, etc.
Thus a few years back when our company entered into contracts with the
insurance industry we did some research (I was part of the research team
and
thus can give you perhaps a better explanation) on this and the final
conclusion which was also acceptable to the insurance industries was the
following definitions, namely:
Lightning affects electronic systems in the following manner:
1. Galvanically coupled surge voltages: Lightning strike air conductors
(telephone line, power line, etc) and the surge voltage is then passed to
ground through the relevant electronic equipment.
2. Induced surge voltages: Lightning strike an object (tree, building,
etc.) and lightning electro magnetic pulsing induce energy into a loop.
damage takes place via equalization.
3. Earth potential differences when lightning strikes a structure. Here
again equalization causes the damage.
The rest, namely surge voltages caused by power grids snap-on, generators
restarting, etc. is defined as power surges not caused by lightning. Thus
lightning have not played a role at all.
So (albeit unfortunately) we have to work strictly within these defined
terms as stipulated in the contracts between us and the insurance
industry.
"ForensicOke" <myforensic@hotmail.com> wrote in message
news:bndce4$49r$1@ctb-nnrp2.saix.net...
Hi Phil!
Thanks a lot for the quick response!
** No problemo.
The whole question surrounding definitions is also an interesting and
sometimes confusing matter. The way you put it was our understanding as
well. Then the insurance industry (our clients) start complaining
because
in
the insurance policies they deal differently with power surge and
lightning
surge. For e.g. the excess fees that the insured has to pay differs,
some
insurance companies here do not even pay out when the claim is
stipulated
as
damage via power surge, some companies here only pay for power surges
when
it is a commercial claim, etc.
Thus a few years back when our company entered into contracts with the
insurance industry we did some research (I was part of the research team
and
thus can give you perhaps a better explanation) on this and the final
conclusion which was also acceptable to the insurance industries was the
following definitions, namely:
Lightning affects electronic systems in the following manner:
1. Galvanically coupled surge voltages: Lightning strike air
conductors
(telephone line, power line, etc) and the surge voltage is then passed
to
ground through the relevant electronic equipment.
2. Induced surge voltages: Lightning strike an object (tree,
building,
etc.) and lightning electro magnetic pulsing induce energy into a loop.
damage takes place via equalization.
3. Earth potential differences when lightning strikes a structure.
Here
again equalization causes the damage.
The rest, namely surge voltages caused by power grids snap-on,
generators
restarting, etc. is defined as power surges not caused by lightning.
Thus
lightning have not played a role at all.
So (albeit unfortunately) we have to work strictly within these defined
terms as stipulated in the contracts between us and the insurance
industry.
** You are on the right track with all the above.
The more likely causes of a pure "power surge" ( not electrical storm
related) involves the accidental contact of low and high voltage AC
supply
wires suspended in the air **OR** the loss ( possibly intermittent) of
the neutral conductor in a three phase supply system ( all systems are
ultimately 3- phase) with consequential sudden increase in the voltage of
one or two phases.
........... Phil
In news:bnbfqr$mhe$1@ctb-nnrp2.saix.net,
ForensicOke <myforensic@hotmail.com> wrote these words:
| BlankIs there anybody out there that can provide me with some advice
| on the testing of computer equipment for traces of lightning damage/
| power surge damage? We test computers for the insurance industry when
| a claimant makes a claim regarding "lightning damage/ power surge
| damage" to computers and computer peripherals.
In about fifteen years of computer servicing I have only come across a
handfull of lightning damaged computers, and of those several have
exhibited very clear signs of damage. One was quite spectacular with a
hole burned into an internal modem where several components just
disintegrated, and another showed signs of damage around the serial port
on the motherboard. In a couple of other cases I have been able to see
no clear signs of any damage, and could only rely on anecdotal evidence.
(For example, the day after a severe thunderstorm someone brings in a
computer which stopped working during the storm.) Thorough examination
of the motherboard may show signs of damage to some of the circuit on
the underside of the board, or there may be no damage evident at all.
I have only once been asked to give an insurance statement regarding
lightning damage to an external modem, and was quite happy to do so, as
my own external modem had been damaged the same day during a storm.
(Incidentally, that was the only time I have had such damage to my own
computers.)
Power surges may cause similar damage, but more often than not I have
found any damage to be in the power supply - I can not recall any case
where there has been motherboard damage which could be attributed to a
power surge.
Obviously my experiences may be different to others. I live in an area
which is not particularly lightning prone, and which has a relatively
stable power supply, so I can only suggest you rely on gut feeling in
the absence of any hard evidence of damage.
--
Cheers
Oldus Fartus
Call me a cynic Oldus, but I'll give 10:1 odds that you could write it"ForensicOke" <myforensic@hotmail.com> wrote in message
news:bndgbl$6q3$1@ctb-nnrp2.saix.net...
| Hi Oldus!
|
| Thanks for the response! Here in South Africa the lightning density
is
| extremely heavy and thus the insurance companies here with which we
have
| contracts, pay out a LOT of claims due to power surge/ lightning
damage. It
| is getting to a situation were the insurance industry are considering
making
| surge arrestors mandatory.
|
| A lot of these claims is BS, but the problem is that there is a
Ombudsman in
| the insurance industry in SA to which every insured whose claim has
been
| denied, can appeal to. Thus we have to make sure that when we have to
| appear before the Ombudsman that we have some empirical proof
regarding our
| test outcome. Thus I have been searching the newsgroups to assist me
in this
| regard. We have to make sure that we are in line with our
international
| brethren in this regard.
|
|
It sounds like you are in an awkward position then, because as others in
this thread have suggested, any such damage may be quite subtle, and not
necessarily where you would expect it.
Fortunately my only experiences with insurance companies have involved
me first. A customer will bring in a computer after a thunderstorm and
examination may or may not show physical damage which, on the balance of
probabilities, was caused by the storm. If the customer was insured I
would give him a report which he then forwards to the insurance company
along with his claim, and generally the claim is paid.
Thinking out loud now - which way do you approach the matter? Are you
looking for evidence to disprove the claim, or evidence to support it?
Then you had better watch out 'certifying' whether something hasI'm a newbie and is still learning along the way.
Nope. No testing of components on the motherboard canThanks for all the answers and advice. My collogues
were right, I should have joined this newsgroup long ago!
Furthermore, I would like to know if there is a way to differentiate
between a power surge not caused by lightning and a spike caused
by lightning by testing the components on the motherboard?
Thats not necessarily true once its onI know that there is a difference in change over time
between normal power surge and surge caused by
lightning (transient much faster in nanosecond)
In theory its possible because very fast rising edges like thatand was wondering if that perhaps can in some way give
an indication on the components which of the two it is.
Yep, and cant possibly distinguish between a power supply thatWe have tried signal tracking but that can only give
an indication of a good, bad, or marginal components
on the mobo and does not help very much.
Yep, you'd be much better off attempting to rub the insuranceNormally we check for lightning activity via the Weather Service in the area
stipulated by the claimant as place of loss, but remember we are in South
Africa! The Weather Service here only keep record of lightning activity and
can not differentiate between whether it was cloud-to-cloud activity or
cloud-to-ground activity. Damage via lightning (we have discussed this
with various lightning experts in the US) can only take place when it is a
cloud-to-ground strike and thus we are back to square 1.
"Oldus Fartus" <denisand@netNOSPAMspace.net.au> wrote in message
news:bnbugk$12lm$1@otis.netspace.net.au...
In news:bnbfqr$mhe$1@ctb-nnrp2.saix.net,
ForensicOke <myforensic@hotmail.com> wrote these words:
| BlankIs there anybody out there that can provide me with some advice
| on the testing of computer equipment for traces of lightning damage/
| power surge damage? We test computers for the insurance industry when
| a claimant makes a claim regarding "lightning damage/ power surge
| damage" to computers and computer peripherals.
In about fifteen years of computer servicing I have only come across a
handfull of lightning damaged computers, and of those several have
exhibited very clear signs of damage. One was quite spectacular with a
hole burned into an internal modem where several components just
disintegrated, and another showed signs of damage around the serial port
on the motherboard. In a couple of other cases I have been able to see
no clear signs of any damage, and could only rely on anecdotal evidence.
(For example, the day after a severe thunderstorm someone brings in a
computer which stopped working during the storm.) Thorough examination
of the motherboard may show signs of damage to some of the circuit on
the underside of the board, or there may be no damage evident at all.
I have only once been asked to give an insurance statement regarding
lightning damage to an external modem, and was quite happy to do so, as
my own external modem had been damaged the same day during a storm.
(Incidentally, that was the only time I have had such damage to my own
computers.)
Power surges may cause similar damage, but more often than not I have
found any damage to be in the power supply - I can not recall any case
where there has been motherboard damage which could be attributed to a
power surge.
Obviously my experiences may be different to others. I live in an area
which is not particularly lightning prone, and which has a relatively
stable power supply, so I can only suggest you rely on gut feeling in
the absence of any hard evidence of damage.
--
Cheers
Oldus Fartus
Not always. I have seen one situation where the power suppliersForensicOke <myforensic@hotmail.com
Furthermore, I would like to know if there is a way to differentiate
between a power surge not caused by lightning and a spike caused
by lightning by testing the components on the motherboard?
IMO "power surge" = lightning induced voltage
spike on the AC suppy - including the earth wire.
And the power lines down the street.Lightning surge = lightning induced voltage spike
on any other thing ( eg phone cables, antennae ... )
have entered into discussion swith only those who put forward arguments"Vermin" <Vermin@nowhere.com> wrote in message
news:7d1lpvcop7ihepf769rh0m6qsef1n3n7qo@4ax.com...
| On Sat, 25 Oct 2003 18:21:31 +0800, "Oldus Fartus"
| <denisand@netNOSPAMspace.net.au> wrote:
|
|
| >"ForensicOke" <myforensic@hotmail.com> wrote in message
| >news:bndgbl$6q3$1@ctb-nnrp2.saix.net...
| >| Hi Oldus!
| >|
| >| Thanks for the response! Here in South Africa the lightning
density
| >is
| >| extremely heavy and thus the insurance companies here with which we
| >have
| >| contracts, pay out a LOT of claims due to power surge/ lightning
| >damage. It
| >| is getting to a situation were the insurance industry are
considering
| >making
| >| surge arrestors mandatory.
| >|
| >| A lot of these claims is BS, but the problem is that there is a
| >Ombudsman in
| >| the insurance industry in SA to which every insured whose claim has
| >been
| >| denied, can appeal to. Thus we have to make sure that when we have
to
| >| appear before the Ombudsman that we have some empirical proof
| >regarding our
| >| test outcome. Thus I have been searching the newsgroups to assist
me
| >in this
| >| regard. We have to make sure that we are in line with our
| >international
| >| brethren in this regard.
| >|
| >|
|
| >It sounds like you are in an awkward position then, because as others
in
| >this thread have suggested, any such damage may be quite subtle, and
not
| >necessarily where you would expect it.
|
| >Fortunately my only experiences with insurance companies have
involved
| >me first. A customer will bring in a computer after a thunderstorm
and
| >examination may or may not show physical damage which, on the balance
of
| >probabilities, was caused by the storm. If the customer was insured
I
| >would give him a report which he then forwards to the insurance
company
| >along with his claim, and generally the claim is paid.
|
| >Thinking out loud now - which way do you approach the matter? Are
you
| >looking for evidence to disprove the claim, or evidence to support
it?
|
| Call me a cynic Oldus, but I'll give 10:1 odds that you could write it
| either way, if the pay and hours were good.
I think you are on the same wavelength as me, so yes, I believe you
could do just that depending on whether you were working for the
insurance company or the claimant.
I guess the lesson here is to get an independent report BEFORE putting
in a claim for insurance. It would worry me that someone working for
an insurance company, in another geographical area, and looking at one
claim in isolation, was able to have the final say in the matter. A
local serviceman is more likely to be able to give a report that there
was a storm on a particular day, and that he had seen X number of
appliances damaged, and so "on the balance of probabilities" this
particular computer was damaged in the same storm, even though there may
be no spectacular signs of damage.
--
Cheers
Oldus Fartus
Particularly when they have no idea what it is they are looking for. ANd
ForensicOke <myforensic@hotmail.com> wrote in
message news:bndac3$2m8$1@ctb-nnrp2.saix.net...
I'm a newbie and is still learning along the way.
Then you had better watch out 'certifying' whether something has
got damaged by a power surge for an insurance company. You
may very well end up with your arse in a sling if you dont watch out.
Thanks for all the answers and advice. My collogues
were right, I should have joined this newsgroup long ago!
Furthermore, I would like to know if there is a way to differentiate
between a power surge not caused by lightning and a spike caused
by lightning by testing the components on the motherboard?
Nope. No testing of components on the motherboard can
ever show more than the power supply did over voltage
the supply rails. It can never distinguish between a badly
designed power supply failing and doint that as it fails and that
being due to a power surge getting thru the power supply.
It isnt normally going to be possible to work that out even from
the power supply itself except in the most extreme situation like
say 11KV or 33KV ends up on the 240V mains for a short time
and blows the shit out of the power supply in the process.
And thats fortunately a very rare occurrence. And is best
worked out from what other houses on that 240V line also
experienced damage to electronic devices at the same time, and
other electronic devices on that 240V line in the same house etc.
I know that there is a difference in change over time
between normal power surge and surge caused by
lightning (transient much faster in nanosecond)
Thats not necessarily true once its on
the 240V line coming into the power supply.
and was wondering if that perhaps can in some way give
an indication on the components which of the two it is.
In theory its possible because very fast rising edges like that
can give the weirdest results on what gets blown and what
doesnt, basically because the very fast edge tends to follow
the path of least inductive/transmission line impedance, but
unless the over voltage is extreme enough to blow tracks
right off, there isnt normally anything visibly fried.
And it can be surprising what survives known very high
over voltages and doesnt die, at least not immediately.
We have tried signal tracking but that can only give
an indication of a good, bad, or marginal components
on the mobo and does not help very much.
Yep, and cant possibly distinguish between a power supply that
has just died and fried stuff powered from it due to bad design.
In other words it just died without there being a power surge.
Normally we check for lightning activity via the Weather Service in the
area
stipulated by the claimant as place of loss, but remember we are in
South
Africa! The Weather Service here only keep record of lightning activity
and
can not differentiate between whether it was cloud-to-cloud activity or
cloud-to-ground activity. Damage via lightning (we have discussed this
with various lightning experts in the US) can only take place when it is
a
cloud-to-ground strike and thus we are back to square 1.
Yep, you'd be much better off attempting to rub the insurance
company's nose in the fact that the only real evidence of what killed
the PC is what other electronic appliances also died at the same time.
"Oldus Fartus" <denisand@netNOSPAMspace.net.au> wrote in message
news:bnbugk$12lm$1@otis.netspace.net.au...
In news:bnbfqr$mhe$1@ctb-nnrp2.saix.net,
ForensicOke <myforensic@hotmail.com> wrote these words:
| BlankIs there anybody out there that can provide me with some advice
| on the testing of computer equipment for traces of lightning damage/
| power surge damage? We test computers for the insurance industry
when
| a claimant makes a claim regarding "lightning damage/ power surge
| damage" to computers and computer peripherals.
In about fifteen years of computer servicing I have only come across a
handfull of lightning damaged computers, and of those several have
exhibited very clear signs of damage. One was quite spectacular with
a
hole burned into an internal modem where several components just
disintegrated, and another showed signs of damage around the serial
port
on the motherboard. In a couple of other cases I have been able to
see
no clear signs of any damage, and could only rely on anecdotal
evidence.
(For example, the day after a severe thunderstorm someone brings in a
computer which stopped working during the storm.) Thorough
examination
of the motherboard may show signs of damage to some of the circuit on
the underside of the board, or there may be no damage evident at all.
I have only once been asked to give an insurance statement regarding
lightning damage to an external modem, and was quite happy to do so,
as
my own external modem had been damaged the same day during a storm.
(Incidentally, that was the only time I have had such damage to my own
computers.)
Power surges may cause similar damage, but more often than not I have
found any damage to be in the power supply - I can not recall any case
where there has been motherboard damage which could be attributed to a
power surge.
Obviously my experiences may be different to others. I live in an
area
which is not particularly lightning prone, and which has a relatively
stable power supply, so I can only suggest you rely on gut feeling in
the absence of any hard evidence of damage.
--
Cheers
Oldus Fartus
Phil Allison <philallison@optusnet.com.au> wrote in message
news:3f9a2e27$0$28123$afc38c87@news.optusnet.com.au...
ForensicOke <myforensic@hotmail.com
Furthermore, I would like to know if there is a way to differentiate
between a power surge not caused by lightning and a spike caused
by lightning by testing the components on the motherboard?
IMO "power surge" = lightning induced voltage
spike on the AC suppy - including the earth wire.
Not always. I have seen one situation where the power suppliers
automatic tap changer failed. That normally adjusts the voltage
the customers see as the load changes, by changing the tap
as the name suggests. When it failed, the voltage supplied to
to the town increased gradually thru the evening as the load
dropped off and ended up frying quite a bit of stuff town wide.
A DEC PDP9 minicomputer, in a big metal wardrobe sized
set of cabinets has an entire column of fans vertically up the
edge of the door that contains all the plug in discrete transistor
modules. As the mains voltage gradually increased thru the
evening, eventually all those fans started to emit a column of
smoke and flames. Fortunately someone was in the computer
room that evening and just shut the system down before the
whole thing went up in flames.
The other not that uncommon situation where you can get
power surges that dont have anything to do with lightning
is when some fool knocks down a power pole, usually with
a car or truck, and the 11KV or 33KV distribution lines at
the top of the poles ends up across the 240/415 lines lower
down the poles for a short time until the system shuts it down.
I've also seen a situation where a storm with no lightning,
just high winds, dropped a branch across the power lines
down the street, with a wet branch forming a conductor
between the 11KV line and the 240V line lower down.
Caused quite a bit of damage to appliances in the street.
You can also get failure of the distribution
transformers the supply authority uses too.
Lightning surge = lightning induced voltage spike
on any other thing ( eg phone cables, antennae ... )
And the power lines down the street.