electric shock from your C2D MBPs?

Discussion in 'MacBook Pro' started by maxxum, Nov 18, 2006.

  1. maxxum macrumors newbie

    Joined:
    Nov 9, 2006
    #1
    Is the widespread shock problem still an issue with the new MBPs? I wasn't aware of this problem when I ordered and now its too late to cancel! My 2.16 C2D is on its way from Shanghai (delayed my shipment, and those overworked Chinese workers most likely ..... lets not go there), so its too late to cancel.

    I am extremely wary of appliances that love giving you electric shocks, my earliest experience of getting shocked was at 7....totally hate it.
     
  2. gr8tfly macrumors 603

    gr8tfly

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    #2
    I think those instances were due to bad grounds when on a/c. It should be solved by using the 3-prong cord (grounded), instead of the flip-out 2-prong. The few posts I read where this occurred, were fixed by getting a good a/c ground.

    edit: you should be able to search those posts for some more technical info on what causes the leakage voltage people were feeling.
     
  3. tejota1911 macrumors 6502

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    Nov 10, 2006
    #3
    I've never been shocked by my C2D MacBook Pro. I think what you have read is a few rare cases. It's not the norm.
     
  4. gr8tfly macrumors 603

    gr8tfly

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    #4
    Agreed - it's rare, and abnormal. Not something to worry about at all.
     
  5. maxxum thread starter macrumors newbie

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    Nov 9, 2006
    #5
    i hope so, i'm in the nyc apple store and have been using a mbp for the past one hour, no shocks so far...but at the same time i don't know if its grounded!!!
     
  6. gr8tfly macrumors 603

    gr8tfly

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    #6
    It's not so much whether the Mac's power supply being grounded or not causing a problem. Those isolated cases were most likely caused by some inadequecy in the facility/house wiring. In those (again: isolated) situations, grounding the Mac's powersupply would eliminate the leakage currents being felt through the case.
     
  7. maxxum thread starter macrumors newbie

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    Nov 9, 2006
    #7
    the side effect of being in the apple store this long is that I got to try out the new C2D mbs too and I'm already regretting buying the 15". Going from 13" to 15" makes the pro seem so bulkier (even when the difference is a 'mere' 2 inches....)

    The MBs seem right for the kind of FOV and attention span I have :mad:
    Maybe I'll buy the santa rosa when it comes out.
     
  8. Glenny2lappies macrumors 6502

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    #8
    They all have earth leaks

    I've a PowerBook 12 and a MBP 15 and they both leak, e.g. you can feel a slight 'buzz' or tingle when moving your hand across the case with the charger plugged in.

    The earth pin is never connected (e.g. when using a UK style mains plug) as there's no third connection. Obviously the US two-pin plug isn't earthed.

    The tingle's less when you rest your palms on the keyboard (you're earthing yourself to the case). It also goes away when using an external monitor - as it's earthed through the cable.

    In reality it's not that noticeable - but it's definitely present.

    As it's my experience with both types of mains adapter (PB & MBP), and that both are switching power supplies as opposed to transformers (which would be very heavy and expensive), I'll make the generalisation that they all leak/tingle.

    Edit: Obviously this affect won't be noticed on MacBooks as they have an insulating plastic case.
     
  9. Glenny2lappies macrumors 6502

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    #9
    How do you ground the power supply if there's no earthing connection? The only way is to have a separate lead from the MBP, e.g. the video cable, to the ground.
     
  10. gr8tfly macrumors 603

    gr8tfly

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    #10
    The extension cable (replaces the 2-prong "built-in" connector) is 3-prong here (US). I haven't experienced the problem myself, but the several reports have said grounding the supply solved the problem.

    The ground from the a/c cord actually goes through the "slide-button", if you know what I mean. If you look at the end that slides onto the power supply, there are metal spring contacts which connect with the "button".

    I did a bit of testing just now, and there is a path from the ground pin to the shield (I have a PB adapter, but I'm sure the MagSafe connector mirrors the connections). I was wondering how the leakage could actually get into the skin of the Mac, so it looks like this is how.
     
  11. Glenny2lappies macrumors 6502

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    #11
    |Not on the UK plug!

    Not on the UK plug! Looking up the plug adapter, there's no metal that would come in contact with the slider 'button'.

    Anyone who's seen a UK plug would know that the earth pin's rather large and important - there's no such thing as a two pin UK plug. In fact it's impossible as the earth pin physically exposes the live and neutral lines (live on the left, neutral on the right).

    It still tingles :p
     
  12. joshstrike macrumors newbie

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    Dec 2, 2006
    #12
    Odd & interesting...

    My gf and I each have an MBP. Neither of us ever had a shock/tingle problem until we moved into this place in South America. However, we are used to using them at 110 voltage in North America.

    We have noticed that other places we plug in here do not always give the same effect. But whatever it is about the wiring of our apartment, there is a _lot_ of excess electricity seeping through the hulls of the computers.

    Hers is worse than mine, and gives painful shocks through the edge of the casing where one's right wrist rests, just above the DVD drive. Mine is not as bad, and can be used without severe pain or cramping of muscles.

    What I'd like to know is: Isn't it the job of the power adapter to discharge of the excess current as heat? God knows that thing runs hot enough. And how much damage is this excessive current possibly doing to my computer? Could using it like this fry the logic board?

    One other thing we've noticed is that our batteries never seem to be completely charged -- they always stick now round 99% and the charger light will stay amber all night. Under the circumstances, we don't have a choice but to shut down and charge them here. I wish Apple had done a better job of this, though. If you're going to make a power supply work anywhere in the world, you'd better make sure it's not going to wreck your computers or shock your customers.
     
  13. Transeau macrumors 6502a

    Transeau

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    #13
    it is a combination of "dirty power" and bad grounding.

    You should pick up a notebook surge protector that has a "propper wiring" light on it. The light will light up green when the power is correctly wired and grounded.
     
  14. joshstrike macrumors newbie

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    Dec 2, 2006
    #14
    Maybe the definitive answer...

    A bit of weirdness. One of our two laptops has been experiencing random shutdowns, so we brought it into the largest apple retailer in the country. While I was there, I checked out the MacBook Pro on display -- and guess what -- it, just like ours in our apartment, gave a buzzing to the fingertips as you passed over it. I asked the sales rep if this was normal -- he claimed not to feel it. An eight year old kid was playing with an iBook and told me it was normal, for MBPs. Another sales clerk agreed, explaining that you "have energy in your body." Which is really funny, when you think about it.
    Perhaps the reason more people aren't reporting this problem is that people in countries with certain voltage levels don't realize that it's not supposed to be like this. The salespeople acknowledged that major electrical shocks were a bad sign; we've had some minor ones from both of ours; but there was apparently nothing unusual about the release of a good deal of electricity from the skins of the laptops. Of course, this never happened under 110V in North America.
    The salesman also asked if, when we plug in our adapters, we see a major, fiery spark from the outlet. We told him yes. He explained that this was a sign that the Apple adapter was properly switching over to 220V power. Funny; we thought it was a sign we were about to burn down our apartment and roast our logic boards...
    Seems like maybe nobody from Apple has gone to test their equipment in South America.
     
  15. Glenny2lappies macrumors 6502

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    #15
    Cough - they also believe in fairies?

    I know that Macs are sold to the 'arty' community of which some believe in everything they're told, but these old boys take the biscuit!

    1 - The reason there's a tingling on the MBPs is the case is made from metal and it's not grounded. There's a small voltage present relative to ground which is passed through one's body. No doubt some people feel it more than others.

    2 - The MBP power supply - in fact all Apple power supplies - are not earthed. They are switched mode power supplies which means they don't have an isolating transformer (otherwise they'd weigh several pounds/kilos).

    3 - The flash seen when plugging in the power supplies is caused when a capacitor is charged. It's one hell of a flash. Again, this is normal for all switched mode power supplies.

    4 - Maybe the salesman in question chooses to ignore the tingle.

    5 - The tingle's felt on PowerBooks as well.

    We could do with someone measuring the voltage difference between the MBP case and ground (when the MBP's not grounded by network, audio or video cables).

    Edit: I dare say that there is a difference between the low voltage mains (110V) in the US/Canada and the rest of the world (230V).
     

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