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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.
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.
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?
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
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
Furthermore, if you ABSOLUTELY must touch something with your bare hand without insulation that you suspect may be electrified, DO IT with the BACK of your hand. This way should your muscles contract, at least you won't have made a death grip on the wire.
That being said... Just don't touch stuff you think is electrified.