Strange vibration felt through fingertips when plugged in

Its a grounding issue. If you're using it on battery power or with the three pronged (US) plug that comes with it, it doesnt happen.

Hello Eriksr,

Same thing with my MBP here. I think there must be some sort of electrical "leak" or something to the machine's chassis.

The question is now: Is this normal?

Later.

I have the very same issue as does a colleague. It is very difficult to ignore and I have to unplug to stop getting distracted. I use a 3 pin plug in the UK so it is not an earthing problem that is being sorted out by using a 3 vs 2 pin electrical connection to live AC.

Apple must be aware of this? Is there a health and safety issue here?

Message was edited by: Andy Tometzki

I do not know if this could be an issue in the long run affecting longevity on HW components. I will run my MBP with the 3-prong (earthed) power cord for the time being. Just in case.

On a different hand, have you guys experienced any Kernel Panics? It seems to be a frequent problem with MBP's and one that has people really mad at Apple.

Sadly, I had my first KP last night.

http://discussions.apple.com/thread.jspa?threadID=1066634&tstart=0

Cheers,

+She suggested I take it to the local Genius Bar. I'm going tomorrow, will update as I learn more.+

If you have one, take a multimeter with you. You'll be able to prove them that there are a few millivolts on the aluminium casing.

It's definitely a grounding issue with me. If I use a 2 prong in he US I get the buzz but if I us a 3 prong I don't. Are you sure your UK plug's earth is connected?

Had the same problem since I got it but never really cared all that much, just thought it was kind of weird.

You're right the universal 3 pin adapter is not earthed (was the one from the travel kit) and I a had changed over the earthed version to my airport express whilst setting up a temp. network whilst on holiday because the reset button on the airport express is in such a difficult position on the casing.

I'll check with my colleague to see if this is also the reason for this. Perhaps there should be a warning on the power supply to make sure you use and earthed plug?

Thanks Andy

I've also been having this sensation - although it seems to have developed somewhat recently. I would agree that it is electrical (and probably grounding). I've noticed that if I have at least 2 points of contact (or my whole palm) on the chassis, then I don't feel the "buzz" or "tingling."

I even took battery out, to see if it was some side effect to the machine after having one of those faulty batteries (which was visibly faulty). No change when the new battery was removed.

Helen

+I would agree that it is electrical (and probably grounding)+

It is definitely related to a grounding issue: as dvbfilth mentionned, if you use the 3-prong extension cord it disappears.

+I've noticed that if I have at least 2 points of contact (or my whole palm) on the chassis, then I don't feel the "buzz" or "tingling."+

You are right Helen, even touching with one finger only the narrow plastic edge which separates the top case (palm rest area) and the bottom case - without touching either the top case or the bottom case - is enough to get rid of the tingling. This is strange, since plastic is a non conductive material.

"You'll be able to prove them that there are a few millivolts on the aluminium casing."

Probably a lot more than that - the power adapter puts one-half of the line voltage onto the chassis. However, since it's at a very low current (within international safety standards). it is neither a health nor safety issue.

I too had this sensation, the country I lived in has 3 pin plugs everywhere and is grounded. Apple supplied me with the Magsafe adaptor brick with the 2-pin and 3-pin interchangable head. The 3-pin head which is supposedly grounded...gave me the stinging sensation on the left and right side of the edge of the MBP ...but infact if u dare to run your wrist around the edge...in front..where the palm rest is which is nearer to the mouse pad... you will still feel the tingling sensation.

I tried using another 3 pin head which I had for other machines. It is the same thing..I could feel the electrical leak or sensation..and also the rubbing of the fingers across the main area of the laptop around the speakers and the back of the LCD screen has this rubbery feel.

The extension cord with the 3-pin head that connects to the magsafe adaptor solves these problem. But I'm not satisfy that Apple shipped a 3-pin adaptor head for the magsafe brick..which is not grounded. (I suspect if you open the 3-pin adaptor..it is actually a 2 pin with just a plastic 3rd earth pin..where they put it just to allow the adaptor to connect to a normal 3 pin outlet).

Is Apple shipping a "fake" 3-pin adaptor so they can save some money??? And why should one feel this sensation? There should not be an electrical leak anywhere. And especially if one can feel pricking, sharp tingling. I have been shocked by a electrical device before, and it does not feel good-I got shocked even though the appliance was grounded. But the appliance was leaking somewhere else.

I request everyone to write a feedback form to Apple. I will write to my local agency on electrical safety to ask them to check on Apple's latest Macbook Pro to see if Apple had failed in this area. I hope everyone can do the same, so that Apple will look into the matter promptly.

You do not play with static of any kind. Even if it's just a small shock, we never know what that may lead into.

I've had success dealing with this - at least for now. I had been using the AC/DC adapter with only my Swiss 2-prong connector plugged in, unlike my experience in the US where I normally used the additional 3-prong grounded cable.

I went and got the comparable cable for Switzerland, and no more buzzing. This is using the same adapter as before. I'm still not sure why the buzzing developed (it wasn't there when I first came to Switzerland over 6 months ago).

Best of luck to the rest,
H.

As everyone else has mentioned this is just an Earthing problem which will go away if you use a 3 prong plug. Here in India this is a perpetual problem with all electronic stuff (despite using a 3 prong plug sometimes), and having experianced this on a daily basis for the last 15 years, I can honestly say it is neither harmful to the user nor the equipment. It just gives a nice tingling wake up buzz. 🙂