Dell Laptops Have Shocking New Problem 475
dapsychous writes "A friend of one of my coworkers has noticed a problem in Dell notebook computers (also covered in this engadget article about a problem that has been popping up lately in Dell 17" notebook computers). It seems that these computers are putting out between 19 and 139 (65 according to article, 139 according to him) volts of AC power as measured from any chassis screw vs. earth ground. This has led to several problems including fried ram, blown video circuits, and a stout zap on his left hand.
According to him, Dell has tried to keep him quiet about the problem and has even gone so far as to have him banned from a few websites, and threatened him with legal action if he tells people about the problem."
Only in America! (Score:5, Informative)
"The latest word is that VG's own problems were solved by springing for a three-pronged grounded power adapter"
You can't get a non-earthed plug in the UK, the earth pin is physically required to open the plug socket. This can be a dummy pin, but you're only able to do that if the unit itself is double-insulated.
Re:Oh shit. (Score:2, Informative)
Watch the ESD (Score:5, Informative)
I worked it out recently when cold winter temperatures drove the humidity way down. Whenever I got up from the couch I would feel the charge build up, then I would inadvertently discharge myself of a light switch, a metal corner post in the drywall, or worse, on some home electronics. After I accidentally blew out the panel of buttons on a DVD player, I did some experiments. By rubbing my hand on the couch cushions for a few seconds, then using a piece of metal held in my hand (less painful that way) to discharge myself to ground, I found I could jump a spark 2 cm or more. Sometimes, I can get multiple sparks on one charge.
It's kind of cool, if you know to expect it. And, the remote still works for the DVD player...
Seems like a SLAPP suit to me (Score:5, Informative)
On what grounds would this be a valid case? Once you sell something to someone that they own (not license), you cannot tell them what they can and cannot do with it so long as you do not cross any other lines and violate someone's privacy (which is why I suppose selling stuff you bought at auction from a storage company is illegal -- although I think most of what those guys did was OK, and the judge overreached). So this guy has every right to say "My computer shocks me, here's what kind of machine it is" because it's not slander, it's the truth.
Seems to me like this guy can file under anti-SLAPP rules, can't he? This company is trying to shut up someone who is exposing their mistakes -- and yes, it is a valid complaint (why wasn't he given a grounded power supply when it is known that failing to ground electronic devices can shock users?) and yes he has the right to be publicly heard if he wishes to. No one has the right to not be offended by what he has to say.
Re:On a couch perchance? (Score:2, Informative)
You are forgetting about the LCD screen backlight, which is powered from a stepped-up AC supply in the notebook. My guess is that this supply is shorting out to the notebook chasis, perhaps in the screen hinge, causing this problem.
Re:I wonder if this has anything to do with (Score:4, Informative)
But this guy says he measured his voltage with the multimeter on AC. Static electricity is the buildup of charge on something capacitive (like you and me) and would be measured as DC. That is, if you could measure it at all, since we make pretty bad capacitors and any ordinary multimeter would quickly drain the charge away.
Re:Why would there be high voltage in a notebook? (Score:5, Informative)
Re:Definitely check your ground... (Score:5, Informative)
I know my house was built a long long time ago (1951) and the upstairs, while someone put in grounded outlets, it doesn't physically have the ground hooked up - due to the wiring used at the time of it being built.
That's an electrical code violation. If you have to have a 3-prong outlet on a 2-wire circuit, you must use a GFCI outlet, which gives you electric shock protection. That's allowed by the US National Electrical Code. The outlet plate should then be marked "Isolated Ground". This warns people that plugging in a computer there may have problems, because it can't dump static and noise into protective ground as usual.
If you're going to wire up power, read a manual on how to do it. It's not rocket science, but there are very specific rules and screwing up is dangerous.
Re:I have the Same Issue (Score:2, Informative)
Re:fix? (Score:3, Informative)
I'm sorry to contradict you but most laptop power supplies are not doubly insulated because the laptop itself is not doubly insulated and you really need to have it grounded in case a fault in the power supply transformer leads mains voltage to the laptop's ground.
If you disconnect the ground or your wiring doesn't have the ground, the EMI filter capacitors will bring mains voltage (albeit with a fairly big impedance) on the laptop's ground. It is not dangerous, but it may create some problem when the laptop is connected to other devices.
The guy should simply ground his laptop power supply.
Article vague, but some hints (Score:5, Informative)
The article is vague. It's not even clear if the problem occurs when the laptop is not plugged into the charger. The power supply for some backlights can produce over 100v, so there is a potential shock source even on battery power.
If the problem is related to the charger power supply, that's a clear safety hazard. Check for a UL logo, and go to the UL web site [ul.org] to check on whether the power supply actually has approval. If the power supply is made in China, it must have a hologram UL sticker with the UL approval number. There are power supplies out there with forged UL approvals, and UL is trying to crack down. (Those are the power supplies that fail in power supply tests on PC websites. UL tests them loaded up to their rated value and runs them for hours at full load, so the UL logo means it really can deliver whatever power it's supposed to deliver.)
37VAC on 15" Dell (Score:2, Informative)
Re:I wonder if this has anything to do with (Score:4, Informative)
Re:I wonder if this has anything to do with (Score:5, Informative)
Re:Only in America! (Score:3, Informative)
1) Theatre lights use them for the simple reason that they don't have a fuse in each plug. Every time a bulb blows it takes the fuse out with it and the last thing you want to do is crawl around the lighting bars looking for a blown fuse. Instead each circuit has a fuse (or nowadays a circuit breaker) back at the dimmer rack. These are the large - 15A - size.
2) Navy ships seem to use them too - I presume for the same reason.
3) Sometimes houses have some of the 2A ones (very small) wired to light switches. You can thus have the room lit by table lights or free standing lights, but still have them controlled from a switch by the door rather than having to go around the room turning them all on and off.
You won't however find any round-pin sockets for general distribution purposes in any UK residence these days - central London or not. The last time they would have been installed would have been in the 1950s, and they'd long ago have been replaced by now.
John
Verified (Score:5, Informative)
I am currently in contact with Dell about this issue and I am being informed they are letting the engineers know of the issue and hope to have a resolution soon.
The funniest thing I have read regarding this was a post in notebookforums from aindfan:
"I took my E1705 up to the Senior Design EE lab here. The two seniors that were there glanced over at my oscilloscope and realized what was going on, most likely assuming that I did not ground properly. When we took it over to the new, more advanced scope, the measurements reported were of a 60Hz periodic function with a peak-to-peak voltage of ~150V.
Being curious EE's, the next natural step that the seniors suggested was to see if we could pull any current out of the screws. A few moments later, we had a circuit with a laptop screw connecting to an LED in series with a 1K Ohm resistor connected to the ground node of a power supply (connected directly to the ground of a wall socket). I am happy to report that the LED turned on and there was a measured current of about 1.4 (mille or micro, I forget which) Amps flowing from the screw to the resistor.
Remember, folks, there will never be current flowing out of the laptop without a load attached to the screws. So don't hook up any 1 Ohm resistors if this is happening to your laptop, you might fry a few things (due to the large current, remember V=IR).
I'm opening up a Dell chat now to see about getting this resolved.
Thanks for starting this thread ViriiGuy. It was quite interesting to play around with the testing for this.
EDIT: When I asked the dell chat support tech if she could send a 3 pronged power adapter (after I explained the issue), she replied "I cannot do that.""
Good stuff.
Re:Oh shit. (Score:5, Informative)
Called them up twice because one of their guaranteed for life tupperware container cracked in my dish washer on 2 separate occasions (similar size/type). They apologized, suggested putting them on the upper dishwasher rack to reduce the chance of this happening, and sent me a coupon good on anything rubbermaid up to the value of the thing that broke. I asked how I needed to send in the broken container (which their warranty terms say you have to do), and they said I didn't have to because they trusted that I was telling the truth.
Otherwise, never had a problem with any of their stuff and the only remotely bad thing that I know of that they did was try to get retirees of a company they bought to pay $40/mo for health insurance.
Re:Article vague, but some hints (Score:3, Informative)
The typical modern CCFL backlight requires 1200V to start up and runs on 400V. The amperage is fairly low.
Re:Non-repro? (Score:4, Informative)
I recomment Vantec's LapCool series, and at about $25 they won't break your wallet.
Re:Non-repro? (Score:3, Informative)
Re:Only in America! (Score:4, Informative)
That's the BS 1363, which was standardised as an electrical appliance connector in 1962. It contains an integral fuse which can be replaced without opening the plug itself, is rated for 13 amps, and is considered by many engineers to be one of the best designed and safest domestic plugs in the world. Most appliances sold in the UK during the last couple of decades have one of these fitted (nowadays usually directly moulded to the cable).
"The socket with three round pins (possibly in two different sizes!)"
They're the older BS 546 type which was originally available in 2 amp (small) and 5 amp (bigger) variants. It's rare to see them as standard electrical appliance connectors in the UK nowadays even in old houses, because they've mostly been replaced by BS 1363 types, but they're sometimes used today for centrally switched domestic lighting circuits, where a fused plug can be inconvenient due to being hard to reach and therefore check / change.
"Also an "electric razor socket" putting out 115V in a bathroom"
You mostly only find these (BS 4573) in hotels and guest houses so that foreigners can plug stuff in without it blowing up. British consumer and safety laws don't allow 115v items to be sold in general retail (although some specialist devices are available for particular applications), so it's very unusual indeed to find one of these in a domestic setting, especially as they're commonly in bathrooms where UK law requires that sockets of this type be connected to an isolation transformer, thus making them rather expensive. A lot of domestic bathrooms do have two pin shaver connectors, but they're usually C17/E "Europlugs" that only output a standard British 240V/50Hz rather than the BS 4573 type.
Re:Verified (Score:3, Informative)
If I disconnect the AC adapter and test the screws again the voltage essentially disappears. From what I have read on other forums the issue seems to be that the AC adapters supplied by Dell are two pronged, no ground, and if you use a three pronged adapter the issue is nonexistent. From my test this seems to support this conclusion.
If you have a E1705 or E1505 I would suggest calling Dell and discussing this with them as I have a feeling if properly tested all newer laptops are having this issue. (Please remember I have only tested 10 laptops which is not a large sample size.)
Re:Oh shit. (Score:1, Informative)
When you use a meter to measure current and power, you select what you want to read, then attach and read it. In this case, it would be either AC or DC voltage or AC or DC current, that is four seperate things and requires moving the selector switch between the seelction to read it.
You can have AC and DC voltage traveling between two points on the same wire. With the AC and DC voltages, you would natually have some type of current flow for each of them as well.
Another issue, if you want to measure current with a standard multipupose meter, current will pass through the meter. You could have NO actual current flow at all but when you hook up the meter, have lots of current flow because the meter is acting as a wire. Try it sometime, place your meter on AC current and attach it to the two prongs on an AC outlet. I bet it will make a loud noise, read the maximum amount of current it can display and then read zero current. The noise will be either the meter breaking, the internal fuse blowing, or a spark or a combination of all of them. The maximum current reading will be just before the fuse blows and the zero reading will be after you broke the meter or blew the internal fuse (Disclaimer: please don't really try this, it is dangerous). The other method of measing current is a "clamp" meter which measures the current flowing through a wire via the magnetic field. Well, if you have no wire to clamp the probe around, what are you going to measure?
So... your comment about messuring the current does not make any sense at all. You would want to read voltage potential between those two points and that is what the person did do. He measured the AC voltage and told us it was between 19VAC and some higher number. You responded with I bet it is DC? How do you think the messured 19-120VAC is going to be DC voltage or how would that AC voltage make DC current? Do you see how your comment makes no sense at all?
Re:Only in America! (Score:3, Informative)
Re:IMPOSSIBLE!!! (Score:2, Informative)
Re:Excuse me? (Score:3, Informative)
Bogus: The real explanation (Score:5, Informative)
Now if you hook a typical $4.99 digital voltmeter from Harbor Freight, the input impedance of the voltmeter, combined with these capacitors, will indicate anything from zero to 377 volts.
And if you rub your cat, the voltage could go much higher!
As you bright folks out there may be guessing, it's not the voltage so much that is the problem, it's the current. And the current is miniscule, microamps.
So no conspiracy here, move along, etc....
Re:Excuse me? (Score:3, Informative)
The quote from the article is:
Re:Non-repro? (Score:3, Informative)
Realistically, I can't see why you'd ever have the voltages claimed by this article inside a laptop. Laptop supplies are usually 24-ish volts. Anybody reporting numbers higher than that probably has something else wrong, like an inverter power cable that is being pinched by a hinge or something. Either way, at the current levels we're talking about, it should be pretty harmless, if a little uncomfortable. However, Dell still should fix their supply design for other reasons.
I was helping someone on one of a recording bulletin board solve a grounding problem with an Inspiron laptop just last week. In that case, the person was getting what appeared to be charge circuit noise in the audio output when the laptop was charging and connected to a properly grounded set of powered speakers. Why? Because the Dell power supply uses a two-prong cord, so the laptop is one giant floating ground, or as it is more commonly known, an antenna. :-) For that reason alone, Dell should correct their prong deficiency.
But yes, the shock would suck, too.
Re:Non-repro? (Score:4, Informative)
Frickin Dell fricken shocks... (Score:2, Informative)
Turns out the idiot user had mistreated her power cord, to the point where the wiring going into the cord had worn away... the covering, the insulation, down to bare copper. In her infinite stupidity, she saw this, and covered it with a bit of black hockey tape, apparently knowing about the magic fix-it properties of hockey tape when it comes to consumer electronics. Of course, even the job she did of taping it up was crap, the tape was coming off, things were shorting out, and in my case, zapping away.
How this woman wasn't reprimanded for extreme stupidity, I'll never know. My employers relative lack of response or sympathy certainly told me a lot about my then-boss.
That's what I think of when I think Dell and shock.
Interesting, my 1705 just blew its video.. (Score:2, Informative)
Re:Um, it is the voltage... (Score:3, Informative)
Almost all devices which utilize wall-operated power supplies can have leakage current associated with them.
A circuit designed as you suggested is a potential lawsuit - if a capacitor shorts, the user gets full line current
Dropping a laptop on your toe is a potential lawsuit. The capacitors mentioned by the other poster are called X and Y caps. Any transformer-coupled switching power supply will electrostatically couple energy from the primary of the transformer, to the secondary. This energy can result in lots of signal integrity related problems in the connected equipment, as well as EMI/EMC issues. In order to minimize these problems, a ceramic capacitor is connected from one leg of the primary, to one leg of the seconday. It gives a return path to the coupled energy. These capacitors have a UL listing that is separate from that of the power supply. They don't fail. Ever. They have a rating of almost 4kV, and are hi-pot tested to that at the factory.
I think it would be nice if the slashdot crowd learned more about the toys we hold so dear. It's worth knowing.
Also, DMM's are very high-impedance, you can measure 'dangerous' voltages by just holding the leads in the air. Like any piece of lab gear, it's nice to know when you can believe it's output.
Don't poop while using a laptop (Score:1, Informative)
I was sitting on the toilet with my Dell on my lap, taking a nice long poop, and I got shocked through my asshole!
re: As long as we're naming "good" companies.... (Score:5, Informative)
I purchased one of their MX1000 laser mice when it was a brand new item, and while it was excellent - my 4 year old dropped it on the floor one too many times. The center rocker button surrounding the scroll wheel started sticking occasionally, causing things to scroll, out of control, in web browsers, MS Word, etc.
Seeing it was under Logitech's warranty, I figured it couldn't hurt to give them a call - to see if they might be able to sell me a used/refurbished replacement mouse inexpensively or something, given the circumstances.
Instead, the sales rep. looked up its serial number to confirm it was under warranty, and simply said "A brand new replacement is on its way." I asked if they needed the old mouse back, and I was told "No. You may as well keep it to have a spare charging base or something." Within a week, a new mouse was at my doorstep, in the retail packaging!
Re:Definitely check your ground... (Score:3, Informative)
You're right; NEC article 406 says that the correct marking is "No Equipment Ground" in that situation.
I had this problem (Score:2, Informative)
However, the problem went away once I came home to the U.S. and I assumed it was related to the 220V service in Israel. Although this doesn't make much sense since the DC power supply should be supplying the same voltage to the laptop in either case.
Re:Bogus: The real explanation (Score:3, Informative)