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My Macbook makes me tingle! Literally!

J

jellybean

macrumors regular
Original poster
Jun 27, 2006
223
15
Hi everyone,
Weird one this... on my new unibody Macbook, whenever I run my finger anywhere over the casing, either on the inside or over the lid whilst it's closed, I get a strange vibrating sensation through my finger! :eek: But only whilst it's plugged into the mains adapter. When it's running on battery power, I don't feel it at all. It's not even a mild sensation, it's rather strong, and runs right the way up my finger. Does anyone else get this on theirs?!
 
No, you're both wrong, I know exactly what they're talking about.

My MacBook Pro did the exact same thing when I first got it, running one or two fingers over parts of the case it will feel as if it's making your fingers vibrate (as in they'll momentarily slide, get caught, then slide again - the feeling that you get if you have your fingers against, say, a cell phone while it's vibrating).

The weird thing is, it only does it, usually, with your fingers, correct? It would only do it with my index finger and my little finger, and if I ran any other part of my hand over the same part of the case it would feel totally flat and I wouldn't feel that 'vibrating' sensation.

I think it's just something on the outside of the aluminum because it's new, I haven't experienced it for over a week now, and even now when I just tried it would no longer do it.
 
This is a mild electric shock. There is either a ground fault or a short somewhere shunting a small amount of power to your notebook's case. I used to get this all the time with my Titanium Powerbook.

Are you in the U.S? Your power adapter probably shipped with two plugs - one small attachment with two prongs, and one long extension with three prongs. I'm guessing you've been using the two prong plug. Try the same thing with the three pronged adapter. If the sensation goes away while using the three pronged adapter, then you definitely have an electrical issue. You could also try the two pronged adapter with different outlets - I used to get the sensation with some, but not all outlets, depending on how the building was wired.

It's not exactly normal, but it is common. You could take it in if it's bothering you, but it probably won't hurt you.
 
Guys, it'd help if you actually read the topic properly.

The OP is not saying it is an actual vibration, they are saying that it feels like a vibration. It cannot be felt when they merely rest their hand on the computer, but when they run their finger from point A to point B. The part in italics means it is not a literal vibration of a part of the computer.
At the moment I seem to be the only one that has posted that has any idea what they're talking about.
 
I get this, definitely feels like a mild static. The strange thing is, I only get it when I'm using it in bed with it propped up on a cushion (plugged into the mains).
It never occurs when I have it on my lap downstairs or on a table.
 
Thanks everyone for the replies. Ivan P seems to know exactly what I'm talking about. Interesting that yours disappeared over time! May just wait and see if mine also stops doing it over time, otherwise I might take it in to the Genius bar, but I'm hoping I don't have to.
 
I know exactly what the OP is talking about. I think its due to the fans spinning cause I can't feel it when I have just woken the computer from sleep and is cold to the touch.
 
Ivan P, I disagree with your assessment, and I agree with those that suggest this is an electrical issue.

The clincher is the statement that it only happens when plugged in, and not on battery power. If it was just an issue with the aluminum surface, it would always be there.

I have felt this issue with my PowerBook in the past, and having done enough electrical work to know what a mild (and not so mild!) shock feels like, I can tell you it is definitely an electrical issue.

Google for "MacBook electric shock" or "PowerBook electric shock". VERY common problem.

Here's a MacRumors thread: https://forums.macrumors.com/threads/36803/

One guy took a voltmeter and measured 50 volts.

Here's a Slashdot article about Dell laptops with similar issues (only on laptops with metal cases, only when plugged in): http://mobile.slashdot.org/article.pl?sid=08/01/17/1748216

One commenter indicates that the "vibration" you feel is the 50/60 Hz AC frequency, expects you'd measure between 5-30 volts, and suspects that the voltage is capacitively coupled between the mains hot wire or the transformer primary. That assessment makes sense to me.
 
I had the same issue with my 12" Powerbook in the past. It was definitely an electrical issue as it would occur only when plugged in and not when running from battery. Oddly enough, I don't have any such issue with my current unibody Macbook.
 
Haha.. I know the thing. It really feels like mild electric shock. Hat it on my previous (not unibody) MBP. Never could figure out what caused that. When i put my palms on the keyboard, I would sometimes get this "shock" from the edge of the laptop where it was touching my wrists...

I just learned to live with that ;-)
 
This is so weird. My moms brand new 2.4 unibody macbook does the same thing. It only does it when plugged in to the wall. It makes this vibrating sensation as you run your fingers or palm along the body, anywhere on the computer. I tried the top, bottom, palm rests. This really sucks. I hope it goes away?
 
notjustjay said:
Dell says it's normal:
http://en.community.dell.com/blogs/direct2dell/archive/2007/04/24/8522.aspx
Click to expand...

Interesting that Dell says it is related to you grounding your notebook (with your body to the earth), but only with notebooks using two-pronged power cords... Last time I checked all Apple MB and MBP power supplies used three-pronged power cords. So I guess Dell's explanation does not apply here.

From Dell said:
The “tingle” sensation is the transfer of energy from you, a 2-wire AC adapter/ system ground and contact with an earth ground. A “tingle” sensation may be felt when touching the exposed metal portions of the notebook and/or 2 -prong AC adapter when the AC adapter is plugged in. The “tingle” sensation is not an indication of a failed or defective ground.
Click to expand...
 
pooky said:
This is a mild electric shock. There is either a ground fault or a short somewhere shunting a small amount of power to your notebook's case. I used to get this all the time with my Titanium Powerbook.

Are you in the U.S? Your power adapter probably shipped with two plugs - one small attachment with two prongs, and one long extension with three prongs. I'm guessing you've been using the two prong plug. Try the same thing with the three pronged adapter. If the sensation goes away while using the three pronged adapter, then you definitely have an electrical issue. You could also try the two pronged adapter with different outlets - I used to get the sensation with some, but not all outlets, depending on how the building was wired.

It's not exactly normal, but it is common. You could take it in if it's bothering you, but it probably won't hurt you.
Click to expand...

This is the closest explanation and pretty much correct. When using the two-prong power cord, there is no earth so it escapes through the case. A feature and not a bug. Use the three-prong and it will go away.
 
Even with my macbook, which is a white 2.4, once I felt this "tingle" sensation when not using the 3-pin adapter. I just touched the dvi ports and usb place and got a lil electricity, but with the 3-pin adapter it goes away :D
 
This happens with my early 08 MBP too. It happens only when its plugged in, and if I remember correctly (haven't done tried playing with it recently) when it was sleeping or turned off. I had fun rubbing my hand over my computer there for a while.
 
UPDATE:

You can feel the vibration/shock when the computer is plugged in and charging. If it is plugged and and full charged, you no longer feel it. Also when the computer is running on battery you feel nothing. SO weird!
 
re

i live in the UK (3 prong plugs) with ground, and i get the same thing, only when it's plugged in (macbook pro unibody) doesn't really bother me as i had the same thing with my original iphone.
 
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