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mutn10

macrumors newbie
Original poster
Feb 19, 2015
23
0
Hello everyone

When my rMBP is connected to charger (most of the time, to save battery cycles) I sometimes feel a tingly feeling when I move my fingers or the palms of my hands over the aluminium. Now I read a lot of people reporting this issue on Apple forums, but nowhere I could find if this is harmful in any way for the laptop or for me. It is connected via a European plug so it is connected to earth.

When I sit on a wooden chair and lift my legs up, I don't feel it anymore so I'm pretty sure there is current and that it isn't the fan or whatsoever.

Also, how can I stop it?

Greetings and thanks in advance :)
 
Last edited:

Blackstick

macrumors 65816
Aug 11, 2014
1,327
6,323
OH
Former Mac genius here... Your two-prong "travel" duck head adapter is likely causing this behavior. It's a harmless tingling, what you're feeling is the aluminum using your body as the ground. You can fix this by using the 5' three-prong cord included in your box which will use the dwelling's ground.
 

MaskedCarrot

macrumors 6502
Mar 25, 2009
464
269
Northern VA
So that's what that cord is in the box when I recently got my rMBP! I was wondering what it would be used for.

But still confusing me though. The OPs problem not withstanding, why would you want to use it anyway? I just plug the brick into the wall just I do my iPad..

Also, how do you attach the cord anyway?

There is nothing included in the pamphlet that comes in the box which says anything about that cord or how to plug it in.
 

IndoX

macrumors 6502
Oct 12, 2011
269
53
Keep in mind that any computer powered on will have some sort of electric static discharge. It may not be enough for most people to feel it, but some people are more sensitive to ESD than others.
 

mutn10

macrumors newbie
Original poster
Feb 19, 2015
23
0
Former Mac genius here... Your two-prong "travel" duck head adapter is likely causing this behavior. It's a harmless tingling, what you're feeling is the aluminum using your body as the ground. You can fix this by using the 5' three-prong cord included in your box which will use the dwelling's ground.

Well as a matter of fact I am indeed using the 5' three-prong cord instead of the travel adapter... So in fact my rMBP os connected to the earth with the cable. :eek:
 

JTToft

macrumors 68040
Apr 27, 2010
3,447
796
Aarhus, Denmark
But still confusing me though. The OPs problem not withstanding, why would you want to use it anyway? I just plug the brick into the wall just I do my iPad..

Also, how do you attach the cord anyway?

- You pull the "normal" plug out of the adaptor, then insert the cord. Here's a handy video with surprisingly many views: https://www.youtube.com/watch?v=QC4DPHPgH2s

Another reason to use the extender cable is that... it's longer.
 

joe-h2o

macrumors 6502a
Jun 24, 2012
997
445
Well as a matter of fact I am indeed using the 5' three-prong cord instead of the travel adapter... So in fact my rMBP os connected to the earth with the cable. :eek:

In that case, are you sure the outlet you are using is earthed properly?

What you're experiencing is the ground "floating" above 0V, so that when you bridge it to ground, you feel a current because there's a potential difference.

With earthed appliances you don't get this, because the third pin ensures that the ground side of the device is actually at ground potential - it's electrically connected to ground.

It's not typically harmful if you can feel the tingling - it's minor leakage, usually caused by a noisy transformer or dirty AC power that is beyond the smoothing of the filters in the power supply.
 

MaskedCarrot

macrumors 6502
Mar 25, 2009
464
269
Northern VA
- You pull the "normal" plug out of the adaptor, then insert the cord. Here's a handy video with surprisingly many views: https://www.youtube.com/watch?v=QC4DPHPgH2s

Another reason to use the extender cable is that... it's longer.

Hey thanks. That explains it.

I still don't see a major need to use it, but I guess it's nice to have in case I do.

Although that seems like an older brick that person has in the video, since mine for my new rMBP doesn't have the clip on the bottom to wrap the cable around.
 

mutn10

macrumors newbie
Original poster
Feb 19, 2015
23
0
Well in fact I only notice it with one specific outlet. Didn't notice it but it must be a bad A/C that is indeed not properly connected to the earth. Now I'm on other side of the room with other plug and I don't notice anything.
 

CaptainChunk

macrumors 68020
Apr 16, 2008
2,142
6
Phoenix, AZ
But still confusing me though. The OPs problem not withstanding, why would you want to use it anyway? I just plug the brick into the wall just I do my iPad..

Because otherwise, I find the cord to be way too short. Plus, the power brick is 3x the size of an iPad's and likes to fall out of my wall sockets in wall wart mode. So at least in my case, why WOULDN'T I want to use it? ;)
 

flur

macrumors 68020
Nov 12, 2012
2,386
1,171
Although that seems like an older brick that person has in the video, since mine for my new rMBP doesn't have the clip on the bottom to wrap the cable around.

The clips are there, they're just pressed in (look on the sides). You can pull them out to wrap the cable if you want to do so.
 

bookwormsy

macrumors 6502
Jul 7, 2010
281
172
Well in fact I only notice it with one specific outlet. Didn't notice it but it must be a bad A/C that is indeed not properly connected to the earth. Now I'm on other side of the room with other plug and I don't notice anything.

If it's only the one outlet, that's probably the issue. It might be worth replacing that outlet.
 
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