Electric shock from MacBook Pro while charging only.

It sound like you are using the two prong that you connect directly to the brick. Try taking that out and putting in the long cord with the three prongs on it. I beleive that your problem will go away.

Especially given drewfisk’s recent reply on this topic, I’m inclined to agree with Peter Arnold1 writing in this thread from several weeks ago. His contribution is near the end. Here it is:

The "pins and needles" sensation you feel as you rub
your finger across brushed aluminum is not an
electrical shock. It is a physiological phenomenon
that occurs when the different sensory receptors in
your fingers receive signals of a certain frequency
generated by the moving the finger across the ridges
of the aluminum surface. It feels a lot like an
electrical shock, but it's not.

You'll notice that if you move your fingers too slow
or to fast the sensation will disappear or diminish
greatly. The sensation will also change depending on
how softly or hard you press your fingers to the
surface. Once the deep pressure sensors get involved,
the brain interprets the signals differently.

I'm not making this up. Its a well-known
physiological phenomenon.

If there were actually a potential on the case, you
would not need to move your fingers to feel it.
Furthermore, the presence or absence of a potential
can be easily determined with a simple volt meter.

Here's another aspect to consider. The output of
wall-wart power supply is isolated from the household
AC. The output is probably around 12 volts and the
current limited to produce no more than 65 watts. You
can put your fingers directly on the terminals of the
power adaptor output and not get shocked. You
wouldn't want to put your tongue on it, but, hey,
there's got to be some line where the responsibility
belongs to the individual.

So, before anyone starts claiming that there is a
power safety issue with the MBP, please get a
multimeter out and confirm it. Tingles as you rub
aluminum proves nothing. Well, actually it does prove
something that is known...your sensory receptors can
produce odd feelings when stimulated in certain
ways.

RRS

iMac 20" Core Duo, 2 GB; MacBook Pro 15" 2.0 GHz, 2 GB Mac OS X (10.4.6)

somoone have reported a similiar problem before and I would recommend contacting Apple ASAP. Someone posted a burnt magsafe on flickr before simply leaving it on charging and I guess his cat walked by it.

I'm getting the same problem. Mini electric shocks when touching any metal part of the MBP. (on charge only)

Other than being quite warm my MBP has been flawless (W8609)

I wonder what can be done about the electric shock situation.

No-one should have electric shock therapy unless absolutely required - Thanks Steve (typing this whilst still getting little shocks......)

MBP2.16 Mac OS X (10.4.6) 2GB Ram 120GB 5400rpm

No 2-pin plug here. 3-pin (3rd being earth pin)

Usually this occurs when earth potential in your house system, starts to float or when the cheap chinese laptop OEM's make dodgy power supplies that have design issues.

I hope the latter is not the case with my MBP. Otherwise apple have another disatisfied MBP customer and I'll my best to get it resolved or warn other people away from MBP purchases - I have had enough of Win/Cheapo laptops, and I thought this would be over once I got an apple - so much for the dream; (continuing mini shocks....)

Thanks for the tip KCH.

Maybe something is getting lost in translation.(see my previous pos)

I am using the the 3-pin/3-core cable. The system is grounded/earthed correctly. (from the laptop side)

Now I have pixels dying on my MBP. (3 so far)

I'm far from happy.(in fact quite ****** off!)
Apple will need to sate my dissatisfaction. As far as I'm concerned, they build quality is not much better than the rest of the laptop munufacturers out there.

So much for being "something special" Steve....I'm contemplating returning my MBP and getting a full refund.

It would be interesting to actually measure the leakage current you are feeling. The maximum permitted is 3.5mA for earthed accessible metal and 0.25mA for unearthed accessible metal.

FLOATING CIRCUITS – PROTECTION AGAINST ELECTRIC SHOCK
http://ewh.ieee.org/soc/emcs/pstc/TechSpk/floating.html

Dual 1 GHz Power PC G4 Mac OS X (10.3.7)

Actually, the users guide does state: “The AC power cord provides a grounded connection." (page 30) and, “For best results, always use the AC power cord and connect it to a grounded power outlet when one is available.” (page 31).
Regards,

2.16 GHz MacBook Pro (W8612...), Dell 620 WorkStation (XP Pro) Mac OS X (10.4.6) G4 Tower (OS 9/10), Dell 620 WorkStation (XP Pro), Gateway P4 (XP Home)

Does anyone with a MBP have access to an ohmmeter? I would like to know the impedance between the MBP case screws and the ground pin at the end of the power supply cord that plugs into the wall outlet. IMPORTANT !!... Do not try to make this measurement with the power supply cord plugged into the wall outlet or with the computer on.


Dual 1 GHz Power PC G4 Mac OS X (10.3.7)

H.F.,

I measure 1 KΩ between the screw closest to the MagSafe socket and the ground pin of the power plug (U.S. version). As expected, the value is the same between the case and the ground connector pin on the power brick. (As you know, the power brick accepts two power connectors, one that has no cord and two prongs and the other that has a cord and three prongs). Shorting the leads on the multimeter shows ≈ 3Ω (of course, I have to change the meter's range to get that value).


Randall Schulz

iMac 20" Core Duo; MacBook Pro Mac OS X (10.4.6)

hey Randy,

Can you bottom line that for us? What do those readings mean? Are they good or bad?

And is it just me, or does this whole discusion about grounding seem odd. I mean how can "slight electrical shocks" be acceptable under any circumstances, grounded or not? I can't think of any other electronic device in the history of the universe where this would be considered OK.

I'm only answering H. F. Cohen's request for a resistance measurement. I'm not an electrical engineer, so I don't know what's an acceptable impedance for this sort of configuration. What does seem odd to me is that particular value. It's as if there's a 1K resistor between the ground on the power supply output side and the ground on the input side.

Keep in mind that unless there's a short between the primary (power line side) and the secondary of the transformer in the power brick, there's no way for line current to reach the computer. That's one big reason so much consumer electroncis equipment has external power bricks. They provide a natural isolation between the device and building power and, if I understand correctly, free the manufacturer from having to get U.L. (and other national regulatorty agency) approval—that's handled by the manufacturer of the power bricks. External power supplies also allow for smaller cases and lessen thermal dissipation requirements.

Anyway, I'm very skeptical that people are experiencing electrical shocks from their MacBooks. There would have to be some serious manufacturing problems for such a defect to occur, and it's not as if power transformers and power supplies are cutting-edge technologies. Of all the things one might expect a manufacturer of computer equipment to skrimp on, power supplies don't seem very likely. The legal liability for a problem with safety consequences is far greater than that for a device's mere failure to perform as advertised.


Randall Schulz

have been reading up on your discussion. small problem.... i have a 17" G4 and I am experiencing the shock problem as well. however it is much more severe on my unit as I feel the shock all over the body, any where i touch the metal, i feel a shock.

i am currently in Hong Kong and just started feeling the problems a few days ago. i went to the local support center and they "claimed" they didn't feel any thing. telling me it is ok that the unit gets warm. i tried to explain that the problem is electrical shock, not heat, but they didn't understand.

needless to say, i am using a grounded power supply. i have tried a different power supply and the same occurs.

at this point,the problem is getting worse and I am getting very worried about i may lose my hard drive. any ideas??