Resolved 2015 rMBP 13 inch - I feel tingling/current

Discussion in 'MacBook Pro' started by mutn10, Apr 14, 2015.

  1. mutn10, Apr 14, 2015
    Last edited: Apr 18, 2015

    mutn10 macrumors newbie

    Joined:
    Feb 19, 2015
    #1
    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 :)
     
  2. ZBoater macrumors G3

    ZBoater

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    Jul 2, 2007
    Location:
    Sunny Florida
  3. JTToft macrumors 68040

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    Apr 27, 2010
    Location:
    Aarhus, Denmark
    #3
    It's normal and not harmful. Never bothered me.
     
  4. Blackstick macrumors 6502

    Blackstick

    Joined:
    Aug 11, 2014
    Location:
    Sunny South Florida
    #5
    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.
     
  5. CaptainChunk macrumors 68020

    CaptainChunk

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    Apr 16, 2008
    Location:
    Phoenix, AZ
    #6
    I guess I never noticed an Apple AC adapter getting noisy because I never use them without the 3-prong extension cords...
     
  6. MaskedCarrot macrumors regular

    Joined:
    Mar 25, 2009
    Location:
    Northern VA
    #7
    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.
     
  7. IndoX macrumors regular

    Joined:
    Oct 12, 2011
    #8
    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.
     
  8. mutn10 thread starter macrumors newbie

    Joined:
    Feb 19, 2015
    #9
    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:
     
  9. JTToft macrumors 68040

    Joined:
    Apr 27, 2010
    Location:
    Aarhus, Denmark
    #10
    - 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.
     
  10. joe-h2o macrumors 6502a

    Joined:
    Jun 24, 2012
    #11
    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.
     
  11. MaskedCarrot macrumors regular

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    Mar 25, 2009
    Location:
    Northern VA
    #12
    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.
     
  12. mutn10 thread starter macrumors newbie

    Joined:
    Feb 19, 2015
    #13
    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.
     
  13. CaptainChunk macrumors 68020

    CaptainChunk

    Joined:
    Apr 16, 2008
    Location:
    Phoenix, AZ
    #14
    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? ;)
     
  14. flur macrumors 68000

    Joined:
    Nov 12, 2012
    #15
    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.
     
  15. inhalexhale1 macrumors 6502a

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    Jul 17, 2011
    Location:
    Ridgewood, NJ
    #16
    Maybe a rubber chair?
     
  16. bookwormsy macrumors 6502

    Joined:
    Jul 7, 2010
    #17
    If it's only the one outlet, that's probably the issue. It might be worth replacing that outlet.
     

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