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Spacemannz
24-08-2004, 09:35 AM
Hey again all. Just thought I'll share this you. If you notice (if you brush your arm, on your case), and you fell power going thru the case. TURN the system off. And get a "sparky" to replace the power point your system is plugged into.

Just over a month ago now, I experienced this "odd behaviour". It took me about a month to figure out why my system was randomly booting/crashing, when previously, there were no problems at all.

(This is using XP).

It was getting to the point, that I was ready to chuck this thing in the bin! Because of the constant crashing. So, I got the mobo, the ram, the cd writer, and the hard drive replaced (under warranty), to see if that would fix the crashing. And it didn't. So, in the end I decided to get in touch with Intel. And removed the CPU packaged it, and then sent it by courier back to Malaysia (Intel Malaysia). It took about 2 weeks to come back. Luckily, I had a spare CPU in the bedroom. As soon as the replacement CPU came back from Malaysia, everything has been fine since.

What (I think) had happened was when the case became "active" due to the faulty power point (it was leaking power), it did more damage to the CPU than anything else (It also leaked power thru the videocard, when you plugged the monitor cable into the videocard at the back). And since it's connected to the motherboard, it would have fried 1/2 the CPU (It would have been like a power surge, altho XP still booted). That was why the system was constantly crashing.

So, if you experience this same behaviour, DON'T turn the system on again, without first getting the power point fixed by an electrician.

Later

Earnie Moore
24-08-2004, 07:11 PM
. If
> you notice (if you brush your arm, on your case), and
> you fell power going thru the case.

You should NEVER get that feeling off any appliance, My Mother told me she was getting a slight tingle off the kettle, when I unscrewed the plug found the earth wire had broken off. (Because I am registered with the Electrical Workers Registration Board)

If you put up with that feeling on any appliance it could led to your DEATH !!!

Spacemannz
24-08-2004, 07:35 PM
Well I know that. Maybe it was the surge protector on this powerboard that lowered the voltage when it made the case active...

Baldy
24-08-2004, 07:47 PM
> . If
> > you notice (if you brush your arm, on your case),
> and
> > you fell power going thru the case.
>
> You should NEVER get that feeling off any appliance,
> My Mother told me she was getting a slight tingle off
> the kettle, when I unscrewed the plug found the earth
> wire had broken off. (Because I am registered with
> the Electrical Workers Registration Board)
>

God forbid have to pay a sparky to change a plug. I rewired my house without any problems whatsoever Earnie, and everything turns off and on OK, without ever blowing a fuse

Spacemannz
24-08-2004, 09:31 PM
Good thing i didnt pay the sparky then lol since I flat. The landlord had to pay.

Billy T
24-08-2004, 09:55 PM
Sounds like the CPU was the problem, not the faulty earth.

Not to minimise in any way the risk of using any electrical appliance that gives you a tingle, but because computers use a power supply system that isolates the input from the output, the absence of an earth simply raises any exposed metal on the case to a voltage determined by the impedance of the sum of the filter capacitors connected between the phase side of the input filter and earth, plus stray capacitance effects. It is usually around 100-120 volts on a high impedance meter, but it can't supply enough current to hurt you.

That is not to underrate the danger either, because if one of those caps breaks down, the outer case becomes live at mains voltage and then you are really in for a surprise.

However, all of that is very unlikely to cause any problems at all for the internals of your computer because that is all supplied by DC fed from the isolated outputs of the power supply. Issues could arise through connections to external devices that are earthed, but they are few and far between in this plastic world.

And especially for Baldy: the greatest risk from home-owner wiring is not the blowing of fuses, it is overheating from excessive load on under-rated cables, phase-neutral reversals, absence of proper earths and loose connections.

Everything seems to work Ok, and they can stay that way for years until one day the mother-in-law drops dead on the floor when she plugs the wrong appliance into the wrong outlet in the wrong room.

Cheers

Billy 8-{)

Spacemannz
24-08-2004, 10:12 PM
Well it was the CPU due to the leaking power... It was OK before then

Would you survive if you were getting shocked inside a case for a month lol. Even at the shop where I brought it, it ran 3 hrs + without rebooting.

On this power point, it didnt or couldnt handle an hour without rebooting constantly. Even when I turned it on first thing in the morning it keeled over.

mr_rix
24-08-2004, 10:34 PM
Try getting your fingers into a switched mode power supply 450w.

Ouch.

mikebartnz
25-08-2004, 02:01 AM
>phase-neutral reversals,
Why they ever change to the universal colours for the wires I will never know because to me red, black and green were very logical whereas brown, blue an green/yellow are not.
Its like NZ Post using blue for fast post and red for standard. It ended up causing endless trouble.

Baldy
25-08-2004, 07:19 AM
> Everything seems to work Ok, and they can stay that
> way for years until one day the mother-in-law drops
> dead on the floor when she plugs the wrong appliance
> into the wrong outlet in the wrong room.
>
> Cheers
>
> Billy 8-{)

Hopefully Mrs T won't read that you would cheer gleefully when your MIL drops dead Billy.

Earnie Moore
25-08-2004, 07:39 AM
The reason is because color blind people can not tell the difference between red & black not sure is green fits in there somewhere.

Anyway color blind people have not problem with the updated color code and if you call a color blind electrician in to your house, you will live longer, that is the thoey anyway.

You could say brown is a faded version of red, (OK)
and blue is a colorized version of black? (what ?)




> wires I will never know because to me red, black and
> green were very logical whereas brown, blue an
> green/yellow are not.

Earnie Moore
25-08-2004, 07:49 AM
The reason is because color blind people can not tell the difference between red & black, not sure if green fits in there somewhere.

Anyway color blind people have no problems with the updated color code and if you call a color blind electrician in to your house, you will live longer, that is the theory anyway.

You could say brown is a faded version of red, (OK)
and blue is a colonized version of black? (what ?)



-------- More --------
By the way taking about logic, some counties in Europe use White & Black for their color everyone here thinks black=negative, white=positive, but in fact it is black=negative & white=positive.






> wires I will never know because to me red, black and
> green were very logical whereas brown, blue an
> green/yellow are not.

Budda
25-08-2004, 08:29 AM
Baldy, its one thing to know what you are doing its another trying to convince the insurance company :(. If you ever have a house fire and they find out it wasnt done by a certified electrician you can say bye bye to any pay out :(. But you can also do the wiring yourself and then get a certified electrician to "certify it".

Murray P
25-08-2004, 10:23 AM
Ernie I thought it was brown, red and green that looked all the same colour to colour blind people. Look at those colours, with the same tone, in greyscale and get the idea. I laso understand that most colour blind people are not devoid of colour in their world but have trouble distinguising certain colours and the aforementioned in particular.

I have come across the old mix the phase/neutral trick a few times or the live conduit is a real doozy. It's always seems to be when the sparky is late and I've been to lazy to walk to the fuse/switch board or figure out which circuit to nix. You can get a crude lesson in how anodising and arc welding work if your lucky.

Cheers Murray P

Billy T
25-08-2004, 10:36 AM
Power doesn't actually "leak" into computers or appliances like that because of a faulty earth (or any other defect in the mains supply side), therefore it can't get really to your CPU, video card or any other part of the electronics. If by extraordinary circumstances and amazing coincidences it did (such as a piece of loose metal or bare wire inside linking the livened case directly to a cpu pin, the cpu would be stone dead, not just malfunctioning.

Power points don't fail suddenly either, so it has probably been like that for quite some time, probably many years. You didn't say what the fault was, but it is usually spread pins in the socket due to metal fatigue, or the earth wire not connected at all. It is quite common in older houses to find that the earth socket is making poor connection and if a house is more than 25-30 years old it is worth getting a check made on any regularly used outlets such as those in kitchens etc.

Cheers

Billy 8-{)

godfather
25-08-2004, 12:48 PM
> Ernie I thought it was brown, red and green that
> looked all the same colour to colour blind people.
> Look at those colours, with the same tone, in
> greyscale and get the idea. I also understand that
> most colour blind people are not devoid of colour in
> their world but have trouble distinguising certain
> colours and the aforementioned in particular.

The problem is that the red perception is usually missing or limited in function. Probably due to reduced "cones" in the retina.
This leads to a lack of ability to correctly deduce colours with any red content.

Its actually described as red-greed colour blindness, and it affects about 12% of males but less than 1% of females. Its hereditary and passed on by the maternal line. Something else we men can thank the ladies for...

Its more complex than just the "grey scale" equivalent.

Perhaps you could borrow my eyes, you may understand?

Test your ability here:
http://www.toledo-bend.com/colorblind/Ishihara.html

Regarding cable colours, shorly it will be illegal to use yellow as a mains cable color in NZ. This is to avoid confusion with Green/Yellow striped cable which is used for earth identification.

Murray P
25-08-2004, 01:58 PM
Interesting to see the different varieties and the effect, 4 types, with 4 sub-types, including 2 rarer monchrome (greyscale like) I might add, with the commonest being the red/brown one. Took a few tests and checked out fine but can imagine by looking at the with - without examples (linked on from linked site) that visual input is quiet different for some and presents considerable challenges in a world devised by and large by and for the norm.

Cheers Murray P

leshibbard
25-08-2004, 04:30 PM
Godfather, that's me down to a "T", Red on Green or Green on Red.

Traffic lights are no problem!! different shades I suppose.

Compulsory Military Training (CMT), I failed on this test but was asked if I would like to do the 14 weeks. Often wondered why!.

Turns out that colour blindness doesn't affect your quality of markmanship, brother and I were classed as top Marksmen, over 95% on all small arms and 6 pounder anti tank gun.

Have replaced a lot of plugs, but have always double checked the embedded letters in the plug.

So that's why the wire colours changed, learn something every day!.

Les 3.

Ps. wished we could sort out these computer problems the same way.

les 3

godfather
25-08-2004, 04:52 PM
> Traffic lights are no problem!! different shades I
> suppose.

Red is always on the top ... ?

> Turns out that colour blindness doesn't affect your
> quality of markmanship, brother and I were classed as
> top Marksmen, over 95% on all small arms and 6
> pounder anti tank gun.

I too had no problem getting a "possible" (100%) in both grouping and accuracy. Perhaps it improves the eyesight for that?

> Have replaced a lot of plugs, but have always double
> checked the embedded letters in the plug.

I have registration allowing me to do it, but perhaps the less said the better ...
Faded flex cores can be tricky. Meggers are useful. When you replace a plug on an extension flex, do both ends.

pulling hair out
25-08-2004, 07:11 PM
Re colour-blindness and shooting.
My brother is colour-blind and does a lot of skeet shooting.
If the skeets are painted orange in colour, and fired off to a landscape where there is a range of green trees, my brother has difficulty in seeing the orange colour of the skeet in the green background of the trees, but is fine against the blue sky.

Also, apparantly colour blind people are very good in the war zone, as they can pick out camouflaged vehicles etc among the green vegetation while on aerial patrol.

regards Marg.

Dolby Digital
26-08-2004, 10:15 AM
>>until one day the mother-in-law drops dead on the floor.
I wonder if she was insured for $10,000,000 :)

leshibbard
26-08-2004, 11:34 AM
>I too had no problem getting a "possible" (100%) in both grouping and >accuracy. Perhaps it improves the eyesight for that?

Did you also notice the peripheral vision was also much quicker on moving targets!.

Les 3.

Vince
26-08-2004, 05:03 PM
The most common form of color blindness is the inability to distinguish between red and green; really dangerous! Vince

godfather
26-08-2004, 06:59 PM
But have you considered the alternate view, that the 12% of us that see things "differently" are the only ones that see it correctly?

The rest of you could actually be seeing things wrongly.

Describe to us the colour Red, the colour Green and the colour Blue, without reference to objects that you believe are Red Green or Blue. Describe the nature of the colour.

To me, I see Red as about 580 nanometer, Green as 540 nm and Blue as 450 nm in wavelength. As you can see, the ability to judge between 540 nm and 580 nm can be very selective. But I believe I am right, do you have the same confidence in your perception?

metla
26-08-2004, 07:02 PM
Perhaps we should vote on the matter?

Big John
27-08-2004, 08:08 PM
> Power points don't fail suddenly either, so it has
> probably been like that for quite some time, probably

You want to bet on that? We saw a number explode the other day. There was a good reason and it was a huge power spike at work that just shorted out everything and ka-blooey.

Big John
27-08-2004, 08:12 PM
> > Traffic lights are no problem!! different shades I
> > suppose.
>
> Red is always on the top ... ?

And did you know that Canada has a different set of rules for traffic lights?

I was on a bus on the way to the skifield and the bus driver was explaining how it worked over there. It goes

Green means go
Orange means go
Red means if I go fast enough I can just make it

Just as he said that he had to brake very suddenly to avoid the car that had crossed through the red light on his right.

And you thought Kiwi drivers were bad.

Billy T
28-08-2004, 01:13 AM
Different sort of problem BJ, we were talking about spread or broken earth socket contacts, or loose earth wire connections, not catastrophic explosion of power system wiring & terminations.

To get the effect you describe, the system would probably need to suffer a 6.6 or 11kv flashover. It won't happen at 230 volts, though once an arc is struck 230 might just maintain it, and 400 volts almost certainly would.

So yes actually, I would bet on that.

Cheers

Billy 8-{)

Big John
28-08-2004, 06:57 PM
> Different sort of problem BJ, we were talking about
> spread or broken earth socket contacts, or loose
> earth wire connections, not catastrophic explosion of
> power system wiring & terminations.

He was talking about explosions.

> To get the effect you describe, the system would
> probably need to suffer a 6.6 or 11kv flashover. It
> won't happen at 230 volts, though once an arc is
> struck 230 might just maintain it, and 400 volts
> almost certainly would.
>
> So yes actually, I would bet on that.

That is correct and it happened at work. You see we generate our own power and do feed the grid. We had huge buildups of salt spray and did have massive flashovers. Made for an awesome light show as well.
Did scare the poor guys coming to work on their little motor scooters though.

Bazza
28-08-2004, 09:46 PM
Who was talking about explosions? Can't recall. Seems it was a problem with 240v wall sockets. And Billy T got it correct. All to do with contacts, & earth connections, so as Billy said, thats the problem.

Big John
30-08-2004, 04:50 AM
> Who was talking about explosions? Can't recall. Seems
> it was a problem with 240v wall sockets. And Billy T
> got it correct. All to do with contacts, & earth
> connections, so as Billy said, thats the problem.

Okay let me rephrase that then. Someone was talking about wall sockets do not suddenly fail. I said you want to bet on this because they do and have done as I said it happened.

Please pay the man his bet.

Billy T
30-08-2004, 10:09 AM
> Okay let me rephrase that then. Someone was talking
> about wall sockets do not suddenly fail. I said you
> want to bet on this because they do and have done as
> I said it happened.
>
> Please pay the man his bet.



Context BJ, context!

I could equally well have said that outlets don't die of lead poisoning, and somebody might then have referred me to a story about a stray shotgun blast.

In an orderly debate, examples quoted have to remain within the context of the discussion, otherwise the chairperson might rule the speaker out of order.:D

I rest my case, age-related earth connection failures in domestic premises are not cause by explosions.

Cheers

Billy 8-{) ;)