Electrostatic sensations from the case of new MacBookPro with new MagSafe

Question

Electrostatic sensations from the case of new MacBookPro with new MagSafe

Just opened a new MacBookPro 15". When the MagSafe power adapter is plugged in, I feel electrostatic sensations (like static electricity) as my hand glides over the surface. These sensations are pronounced, but disappear when:

1. My other hand simply touches the Mac anywhere and simultaneously, and/or

2. The power adapter is removed to pulled from the AC or

3. The original style MacSafe power adapter is used.

It's not polarity nor the AC of my residence, as I've tried this in other environments.

Those of you with the mid-2012 MacBookPro with HiRes Display please plug in your MagSafe adapter so the battery is charging and try this: With only one hand (preferably the side of your hand near your baby finger), rub over the top surface anywhere. Then try the same thing with the MagSafe removed. Then put the MagSafe back in so the charging light appears, and rub the surface again using only one hand. If you feel the static-like sensations, continue doing that but simultaneously touch the computer with your other hand.

Do you experience the issue described above ? Unclear if it's my Mac and/or the MagSafe.

Possibly related threads: https://discussions.apple.com/thread/3339933?answerId=16205264022#16205264022

https://discussions.apple.com/thread/3821358?answerId=18097872022#18097872022

MacBook Pro

Posted on Jul 7, 2012 12:03 PM

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Answer 1

carl wolf

Level 6

14,625 points

Jul 8, 2012 4:15 PM in response to MacPcConsultant

"Their remedy is to use the three prong cord to the transformer, and to not plug the two prong adapter directly into the wall."

Exactly as I recommended.

In order to meet international standards for radiated emissions, the power adapter places one-half of the AC line voltage onto the computer chassis (and, therefore, the metal case). Although annoying, the current level is well below international safety standards, and is not hazardous. Properly grounding (3-prong AC input cable, plugged into a properly grounded AC outlet) completely eliminates the sensation. All manufacturers, not just Apple, use this scheme. If the computer does not have a metal cover ("my Dell is OK"), you'll not notice the sensation, because plastic does not conduct electricity.

Finally, the ground and neutral wires are different and separate.

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Answer 2

Shootist007

Level 6

16,703 points

Jul 7, 2012 12:08 PM in response to MacPcConsultant

Take it back and get another.

Yes there are other posts about this. Some do it other it seems don't.

Return it for full refund and then buy another. If the same thing happens do it again, and again, until you get one that doesn't do it.

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Answer 3

Jul 7, 2012 4:34 PM in response to Shootist007

Thank you. You must be correct because the unit induces that creepy sensation ONLY when charging and only with the new style MagSafe. Once charged, even the new MagSafe which came with this new laptop does not produce the static sensation.

Wonder why the old style MagSafe (from ye olde black MacBook days) doesn't cause this when charging this laptop ?

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Answer 4

carl wolf

Level 6

14,625 points

Jul 7, 2012 5:00 PM in response to MacPcConsultant

The sensation is due to the fact that the power adapter is ungrounded. Use the 3-prong AC input cable to the power adapter, and assure that it is plugged into a properly grounded AC outlet.

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Answer 5

Jul 7, 2012 5:15 PM in response to carl wolf

The power adapter is indeed and has been plugged into a proper three hole grounded outlet, but the transformer has only two blades so it cannot be connected to the ground portion. Even if you were correct, why the difference between the two MagSafes ?

Now it's occurring, but to a lesser extent, even after the Mac is fully charged, but again, only with the new MagSafe.

NEW INFO: When the old style MagSafe is in the new MacBookPro, whether fully charged or not, there's no static sensation. I left the old style plugged into the MBP, but just by chance I picked up the unattached end piece of the new MagSafe with one hand, while touching the MBP with the other hand -------> the sensation returned. Whatever is happening went across my body.

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Answer 6

Jul 7, 2012 5:40 PM in response to MacPcConsultant

Addendum:

When testing the above, I was wearing socks and standing on a wooden floor. With my shoes on, the sensation is reduced by about 60%.

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Answer 7

Shootist007

Level 6

16,703 points

Jul 7, 2012 5:56 PM in response to MacPcConsultant

Really this should not happen. I don't have it on my 2011 model MBP and not on my newest Dell E6420 bought in December of 2011. If I did I would return it.

Also the ground lug really isn't needed. The neutral wire, white, is connected to the same bus bar as the ground wire, bare, in the electrical panel. The unit should be grounded even if the 3 prong power cord isn't used. And the AC side is separate from the low voltage side. That is what the transformer does.

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Answer 8

Jul 8, 2012 3:31 PM in response to Shootist007

Spoke with AppleCare. Initially they were peplexed and the issue was escalated. Fianl answer: "It's a known issue in some models, but not a hazard therefor nothing to fix or repair". Their remedy is to use the three prong cord to the transformer, and to not plug the two prong adapter directly into the wall.

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Answer 9

Jul 8, 2012 8:49 PM in response to carl wolf

Yes, you did recoimmend that. Thank you. HOWEVER, I went to an Apple Store with my adapter. Checked their MBP Hi Res which they said was grounded, and that creepy sensation was present just as it was positioned there for customers to use.

Had two salesmen try it and they were surprised over the disconcerting sensations. But get this. I plugged in my new MagSafe adapter in an outlet WITHOUT using the three prong cord and the static like sensations disappeared. Changed back to the grounded store MagSafe, and the sensations came back.

So the three prong with ground might be an answer, but it is not the entire answer. My friends and associates with metal-cased computers don't have this problem. I checked all of the MBP Retinal Displays in multiple stores and they didn't have this issue.

I go to many homes which do not have a ground AC outlet. This disconcerting static-like sensation might be safe, but it's not comfortable nor reasonable to have in this $2,500 laptop. So unless there's a remedy without grounding, returning or exchanging this MBP is the answer. Apple has some research and revamping to do.

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Answer 10

Jul 9, 2012 10:27 PM in response to Shootist007

Thank you. Ordering another MBP Non-ret 15" per your suggestion.

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Answer 11

Jul 17, 2012 12:29 AM in response to MacPcConsultant

Yes, you did recoimmend that. Thank you. HOWEVER, I went to an Apple Store with my adapter. Checked their MBP Hi Res which they said was grounded, and that creepy sensation was present just as it was positioned there for customers to use.

My ungrounded MS2 transformer eliminated the electrostic buzz caused by Apple's grounded MS2 adapter. Anyone have insight as to why this occurred ?

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Answer 12

BigDag

Level 1

1 points

Jul 22, 2012 10:10 AM in response to MacPcConsultant

Not a problem on my MagSafe MBP which has high res :)) a friend of mine who works for Apple said there is no known issues you describe, check your house wiring out.

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Answer 13

Shootist007

Level 6

16,703 points

Jul 22, 2012 10:13 AM in response to BigDag

BigDag wrote:

Not a problem on my MagSafe MBP which has high res :)) a friend of mine who works for Apple said there is no known issues you describe, check your house wiring out.

That is the Canned Apple response for all things like this. They always say "Never heard of it before". When in fact they have.

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Answer 14

Jul 23, 2012 3:27 PM in response to Shootist007

Some posts were deleted here, especially the one in which I stated that I was aware of an Apple internal document acknowledging this substantial problem, but stating that there would be no repairs since it was "not a health risk".

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Answer 15

Courcoul

Level 6

18,558 points

Jul 23, 2012 4:12 PM in response to MacPcConsultant

MacPcConsultant wrote:

The power adapter is indeed and has been plugged into a proper three hole grounded outlet, but the transformer has only two blades so it cannot be connected to the ground portion. Even if you were correct, why the difference between the two MagSafes ?

Oh, but it is. Not thru the two round prongs deep inside the power brick, but to the metal button the cable clicks onto. As for the difference, I guess it is just a marketing ploy, as both have the same wattage rating. Unless they decided to change the DC voltage too: my traditional brick says it puts out 16.5-18.5 VDC @4.6A max.

When unable to use a three-prong fully-grounded outlet, you can always try to flip the brick around and see if connecting the "duck's bill" one way leads to less sensations than the other. After all both prongs are the same width, they're not polarized.

Finally, when in a pinch to connect to an unpolarized outlet and if you left the duck's bill adapter behind, you can also use the regular power cord found in many other power bricks, that features a "figure-8" plug instead. Fits the Apple adapter perfectly, skirting the metal button.

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