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.'"

Technically it's bad design...

[Animaether]

...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.

Re:xps m1330 owner here

[Alioth]

They probably are. Having lived in both countries, where most UK devices are almost always properly grounded (the earth pin is not optional in UK power plugs because you physically can't plug something in that doesn't have one - the earth pin opens the shutters in the wall socket), a great number of US appliances lack a ground pin.

Perhaps because 110 volts is seen to be less dangerous than 240v, it gets omitted.

The 3rd pin isnt much different from the neutral

[Tmack]

Since the "neutral" line is actually ground as well (it ties to the grounding bar at your breaker panel), the "Ground" wire itself is really just an extra protection in case one of the wires goes bad or electricity flows to where it shouldnt. This case of electrical shocks (pun not intended)is due to improper grounding in the power supply brick of the power going from it to the laptop itself, and of the laptop's case against the innards of the machine. If it were just the lack of a 3rd pin on the power brick, then why does my macbook (and why did my powerbook before that) never shock me (both have a 2prong only plug, or 3prong cord, never been shocked with either in use)? It is simply a poor electrical design. And the "tingly" feeling is most likely AC current (dc would just lock your muscles, AC makes you twitch), rather than simple static buildup, meaning the circuits are actually leaking AC current from somewhere to the case, which should never happen since the power brick should only be sending DC to the laptop.

tm

Re:Forget exploding batteries,

[einhverfr]

Customer's shocked by Dell's high-performance Laptops!

Actually, on one of my trips to Indonesia I had a similar problem with my (three-prong) Compaq Armada. If I touched any exposed metal on the case, I might (or might not, depending on the circumstances) receive an electric shock.

In that case though the problem was not due to the laptop but rather faulty building wiring. My guess is that either the earth ground was not attached to the wall socket properly or somewhere else a lot of electricity was being dumped down the earth ground, changing its electric potential.

Re:How the hell did they get it UL listed??

[milsoRgen]

I remember years back watching a Dateline or some such nonsense on UL. Long story short... They are not worth the ink used to print their logo. Just a case of too much to do and too little time. This could of changed by now. But I really put no stock into UL certification.

Re:xps m1330 owner here

[pcgabe]

It's even worse in Japan. You can't physically plug something in that DOES have an earth pin; the sockets aren't made for them. There's no grounding at all*. I guess 100 volts must be safer than 110v.

(* not entirely true, some outlets have a grounding tab on them, to which you can attach a grounding wire from certain appliances. But not every appliance, nor every outlet. Or even most. Or half. My last apartment had two outlets with grounding tabs on them, total.)

Cuba and non-grounded 220v...

[PhotoGuy]

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.

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. :) Check out the photos. [gass.ca]

NO NO NO

[Anonymous Coward]

You want the ground wire to maintain its integrity as long as possible under fault conditions. As long as the ground wire is intact, the case etc cannot reach a potential very much higher than ground, so you can't get a shock. Even if the phase wire somehow shorts inside to ground, you want the ground to maintain the case at ground potential until the switchboard fuse or breaker opens and disconnects the supply.

If the case does get struck by lightning, well, the wire will probably vapourise anyway, and you will be in deep doodoo anyway, but the fuse would not have made things any better. (The vapourised wire and fuse would all keep conducting long enough for the strike to finish anyway, at which time your charred remains will fall to the floor...)

So remember, when a fuse blows or a breaker pops, if you fix it and it goes again, there is a more serious fault somewhere else. Fuses can go from old age, and breakers can open from one off surges, but if they keep popping there is something seriously wrong downstream. Do not replace a fuse with one with a higher rating as a fire may really spoil your day.

Fianlly, the original suggestion of adding an earth has its merits, but needs to be done properly to maintain safety. You really need to check your local regulations before doing this sort of thing. You can void your insurance even if there is no actual problem with the way you have done it. This will depend where you are, and I am probably not in the same country as you so I will not presume to tell you what you are and are not allowed to do.