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New Dell Laptops Give Users a Literal Shock
An anonymous reader writes "According to CNET.co.uk, certain new Dell laptops with a brushed-aluminum finish are giving users more than they bargained for. 'We know this because several CNET staff were hit with an electrical charge while using Dell's new XPS M1530 — and we're not the only ones. Dell's forums are littered with user complaints about the shocking experiences they've had with some systems. The problem only seems to occur in Dell laptops that have a brushed-aluminum finish. These include the XPS M1330 and XPS M1530. It's caused by the two-pronged connection between the mains lead and the power adapter, which isn't earthed properly because of its lack of a third pin. The laptop therefore exhibits an electrical potential (voltage) between its exposed metal parts (the brushed aluminum wrist pad) and earth ground. Since there is no earth, the human body basically acts as a wire that can conduct electric current, hence the tingling, jolting sensation.'"
This is the new ground breaking experience with laptops!
Where can I get one? I need a presant for my mother in law.
Someone save me from this sanity.
To be fair to Dell this happened on my PowerBook and not so much on my MacBook Pro... But sometime I do get a tingle, in the right condition.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
...what happens when you lick it?
Better or worse than a 9V battery?
"Dude, you've got a Dell!"
Windows 3.1x calc: 3.11 - 3.10 = 0.00
The Apple PowerBook G4 aluminium systems have also suffered from this - but only when using the 2-pronged power plug. If I use the actual cable between the power adaptor and the wall (with three pins) then this is no longer an issue.
I believe the MacBook Pros also suffer from this however I haven't tested this.
Don't shock me bro!
Knowledge is power. Knowledge shared is power lost.
I've had an aluminum-brushed XPS m1330 for about four months now, and I've never experienced a "shock" like the article is suggesting. I don't doubt that the CNET editors have experienced this, but I'm certain I would have remembered it if it had happened to me.
I checked, and my 1330 has a grounded three-prong plug going into the wall, and a three-prong plug going in to the power brick. Maybe the UK 1330s/1530s are different than the American ones?
The machines have struck the first blow!
If you can read this, I forgot to post anonymously.
the two-pronged connection between the mains lead and the power adapter, which isn't earthed properly because of its lack of a third pin.
That explanation is over simplified. Tons of metal-encased devices have only two-prong leads and are perfectly safe. My Apple laptop for one, and a lot of stereo equipment as well.
UL allows this if the device is sufficiently isolated. What is sufficient depends on the type of device, the type of power supply, whether the supply is internal or external, and so on. Usually it means that the DC output of the power supply has a very high impedance with respect its input, and also that the metal chassis of the device is floating (with specific distances and or dielectics between it and any possible potential) and/or has a non-conductive finish. I'm not sure but I think even just clear anodizing would meet that requirement. I just tested my MacBook and all the aluminum surfaces are not conductive, suggesting such a finish.
In order for the Dells to be zapping people they must have doubly screwed the pooch: wall wart is putting out a high potential, AND the case is not properly insulated.
It keeps you awake in those meetings that seem to take *forever*.
Just keep in touch with your Dell laptop.
Windows 2000 - from the guys who brought us edlin
I guess you could say that the folks who bought these laptops got a shockingly good deal.
Do or do not. There is no try. --Jedi Master Yoda
"We deny all charges."
Authority questions you. Return the favor.
...after all, no part of the casing *should* be making contact with the electrical parts at all. The whole thing with making the casing grounded is for the unfortunate event that it does; typically as the result of some manner of physical malfunction within (e.g. a wire coming loose).
That said - my acer laptop has a brushed aluminum finish and has the same problem *if* I don't plug it into a grounded wall outlet (as it currently isn't). It doesn't feel so much like a jolt or a tingle, however, as that the surface feels strange.. almost like it's vibrating at a high frequency; but only when touched very, very lightly.. a firm touch increases contact area and away goes that odd feel.
Surprisingly, the metallic finish (probably aluminum as well) on my USB keyboard has the same thing going on.
Again, though, if plugged into a proper outlet, the problem goes away.
It seems fairly common for the housings of low-power (and yes, a laptop is pretty much low power; although a 'jolt' sounds light it might be otherwise.. high performance gaming laptop sucking 150W+ perhaps?) to not be properly insulated, though.. I can probably walk around the house and find a dozen more appliances that exhibit this.
tm
Support TBI Research: http://www.raisinhope.org
The engineers giving in to the Helpdesk people.
Think of the possibilities!
Tech: Ok, put your mouse over the 'My computer' Icon and right click...
Guy: Why does this have to be so complicated? Why doesn't everything just work right the first time? You Idiots should be shot!
Tech: Well Sir, if you would just...
Guy: I'm tired of you people and your attitudes, why I should...*ZAP* AHHH! WHAT THE HELL WAS THAT?
Tech: Now what did you learn?
Guy: I'M GONNA KILL...*ZAAP* AHHH!
Tech: A bit slow today are we?
Cut open an unplugged three prog extension cord, exposing the three wires inside.
Cut open Dell power cord, exposing the two wires inside.
Position pieces of heat-shrink tube over the stripped inner wires to be joined.
Connect positive extension cord wire to positive laptop wire and solder.
Connect neg. wire to neg. wire and solder.
Connect the third ground wire to the exterior casing of the laptop with tape as to be removable.
Cover over the sealed three wires with heat shrink or electrical tape for asthetics.
Disclaimer: I'm assuming everyone here knows what they are doing. Mains power can be very hazardous and very deadly. Do NOT attempt this if you are unsure of what you are doing -- call someone more experienced if in doubt. But for those of you who know what you are doing, this should be an easy fix to avoid the shock of you being used for a ground wire.
Windows has detected an undetectable error.
Neutral is neutral and ground is ground. The fact that they are connected to each other at the service entrance does NOT mean that neutral can be used as a ground reference.
From the device's perspective, neutral must be treated as AC line input, never ever ever as a ground.
Any number of wiring faults could cause the neutral to become hot, and even under normal circumstances it is common to see some potential on neutral relative to ground, because loads on the branch circuit are pulling it towards one phase or the other.
In Australia we use the terms "earth", "active" and "neutral", coloured respectively green, red and black.
There is no need to be *shocked* that other conventions exist. "Earthed" is not wrong, it's not slang, it's just not standard in the US.
In most times, most places, by most people, liars are considered contemptible. - Ursula Le Guin
Hey, fanboy. Stop your drooling for a few seconds and re-read that he said it happens with MacBooks. Not *all* Mac Books. It doesn't happen with *all* individual machines in that Dell (or Toshiba, etc) line, either.
There's nothing magical about the components in an Apple laptop (probably using almost the same damn parts) that makes grounding and electricity work differently.
Not possible. A UK socket physically *requires* that a ground pin be present. The ground pin is a bit longer than the live/neutral pins, and is used to open a "shutter" blocking the live/neutral holes when the plug is inserted. When the longer ground pin is inserted, the shutter opens, allowing the plug to be fully inserted.
As an additional safety precaution, every plug is also fitted with a 13A fuse, and all domestic circuits fitted with the connector described above are *explicitly* rated to operate at up to 13 amps. (Additionally every single wall socket also has an individual on/off switch)
The UK/Ireland wiring standard is arguably the safest in the world, and makes the North American NEMA standard seem primitive and dangerous by comparison, as outlets are not shuttered, circuits do not have an explicit amperage rating, and no ground pin is required.
(There's also an older 15A British standard that's still used in some former British colonies and dimmable theatre installations that lacks the fuse and shutter mechanism, and is electrically compatible with the "new" standard with the use of an adapter, despite lacking the newer standard's safety features)
Mind you, the ground pin doesn't actually have to be connected to anything, nor would one expect it to on a laptop, considering that no grounding is possible when the laptop's running off of battery power, nor should AC power ever even enter the laptop's chassis.
Sounds like either Dell screwed up the design, or CNet installed carpeting in their UK office.
-- If you try to fail and succeed, which have you done? - Uli's moose
...I had the bright idea of touching a 9 volt battery to my *braces*.
I couldn't tell if the bright white flash/pop that followed came from just in front of my face, or from somewhere inside my head. Painful to say the least.
Can someone explain what happened?
Last year, I posted detailed information on the tingling sensation sometimes associated with leakage current http://direct2dell.com/one2one/archive/2007/04/24/8522.aspx. Since the story, I re-visited the issue with members of our Engineering team. Here's what they had to say: Even though the leakage current is extremely low and well within safety limits, it is perceptible by some people. This perception may be experienced as a mild "tingling" effect. However, if that "tingling" effect is coupled with an electrostatic discharge, such as is experienced when walking on carpet in dry conditions, the total effect can be surprising but not harmful. The primary effect being felt is from the electrostatic discharge (static electricity). Typically the tingling sensation can be eliminated with a three-prong adapter, however a three prong grounded AC adapter will not eliminate the electrostatic discharge. The tingle is not harmful to the users or the system components. Again, more details about the tingle sensation are available here. http://direct2dell.com/one2one/archive/2007/04/24/8522.aspx
Reminds me of a trip to Cuba last year. The power in the rooms was 220v, with no ground plug. Many consumer electronics, including my wonderful little Toshiba Libretto (now *that's* a sub-notebook, Apple) work fine on 220, the switching power supply just regulates it properly.
:) Check out the photos.
However, I had to bend the ground pin out of the way to plug it in. Things charged and worked fine. However, apparently the brushed aluminum case wasn't quite at true ground with this arrangement. It was more than tingly (if your feet were on the ground; if you lifted them, it was fine). I made a point of only using the power supply to charge it, then use it on battery power, for safety's sake.
It was interesting to see the cavalier attitude towards electricity down there. A worker was doing some construction with an electric drill outside our room; the drill obviously only took 120v, as he hooked up a transformer in our *bathroom* (which was near the door) to power his drill. It was connected to the plug with wires jammed into the outlet, and to the drill by wires wrapped around the prongs. Scary stuff. We stayed clear of our room that day.
Love many, trust a few, do harm to none.
He's correct. It's a safety issue.
Also, prolonged contact with (nearly) ANY electrical current that you can feel can become dangerous. While a low voltage won't be able to pass much current through the skin (skin resistance) initially, this situation will change. As voltage flows skin resistance slowly decreases, and can lead to fatal currents if allowed to persist for long enough.
Effects of current through the human body (rough):
0.2 amp - no fibrillation. Severe burning and breathing halted.
0.1 - 0.2 amp is the most dangerous zone, because fibrillation is a faster death and harder to stop than a mere stoppage of the heart as occurs above 0.2 amp.
Skin resistance is about 1kohm for wet skin and 500kohm for dry skin. Internal resistance is 100-500 ohms, so current penetrating the skin is what causes problems. Higher voltages let more current through, so above 240V current easily penetrates the skin. If you touch a wire of 0.02 amps or so your muscles will contract, forcing you to hold onto the wire. Since skin resistance drops over time you will soon find it difficult to breathe and eventually you WILL die.
If you find someone stuck to a wire in this manner, the person WILL die if they are not removed. Do not attempt to touch them uninsulated, since you will likely become stuck yourself. Turn power off, or push them off with a stick or other non-conductive object.
Not a sentence!