Sparks from USB ports!

Discussion in 'iMac' started by diegobgr, Aug 26, 2010.

  1. diegobgr macrumors 6502

    Nov 22, 2009

    I have noticed that my iMac makes sparks when I try to connect something to the USB.

    I think that there are only make when it's something with external power, like a printer or a external hard disk. With a pen-drive or the iPhone, it doesn't happen.

    What can you tell me about this?
  2. 01jamcon macrumors 6502a


    Jul 24, 2006
    That really isn't normal. Is your desk made of metal cause that can cause a weird transfer of current between devices. There shouldn't be sparks out of a USB as its only putting out 5V which is nowhere near enough to make a spark.
  3. nobias macrumors regular

    Jun 23, 2010
    Holy *****
  4. eddvedd macrumors regular

    Apr 28, 2010
    Dude, just so you know, there are enough amps in a USB port to kill you. Seriously!!!! Don't touch that computer until you take it in to get it fixed.
  5. JAPears macrumors member

    Jul 17, 2010
    It's pretty normal, I assume the sparks you mean aren't as big as what people seem to be assuming from your statement?
  6. zViiPeR macrumors member

    Jul 30, 2010
    What iMac do you have? My 2010 27" iMac does this when i plug in an externally powered device (printer, hard drive dock, etc.) I have also been wondering if this is normal.
  7. MadMitch89 macrumors regular

    Mar 31, 2010
    Brisbane, Australia
    Mine also does this. I need to take my new i7 to the Apple store to get it looked at for HDD noise, should I get this checked as well?
  8. diegobgr thread starter macrumors 6502

    Nov 22, 2009
  9. byron_hinson macrumors 6502

    Jun 3, 2003
  10. Illuminated macrumors 6502a


    Sep 25, 2008
    mine doesn't do that...maybe you mac is touching something metal?
  11. mulo macrumors 68020


    Aug 22, 2010
    Behind you
    that is definitely not normal... I'd go get it checked if I were you.
  12. aliensporebomb macrumors 68000


    Jun 19, 2005
    Minneapolis, MN, USA, Urth

    USB ports DO have power coming out of them.

    But this doesn't sound normal.
  13. diegobgr thread starter macrumors 6502

    Nov 22, 2009
    So, it's normal?

    People taht say that it doesn't happen, could tru it? It doens't happen always.
  14. Dansk macrumors member

    Apr 15, 2008
    I used to get this on a G5 with firewire devices pretty regularly. Just little tiny sparks that jump between the cable and the area around the port on the tower. Freaked me out at the time
  15. wombatwod macrumors newbie

    Sep 9, 2010
    Sparks from Macbook usb ports

    I'm having my brand new Macbook pro tested at an Apple shop right now for this problem. In my case, as well as the sparks, the remote monitor (running from the mini display port) gets shutoff, then fills with static.

    Apple support say they've never heard of this problem so I pointed them to this forum. However, they say it should not happen, so that's why it's being investigated. Don't think this is normal, as some people are posting. It may not damage you but it may well damage your computer.

    It seems to happen with USB hubs. I've tried it with two different brands and two different cables and it occurs in both cases. I can't get the problem to occur on my son's identical Macbook.

    So if it happens take it up with Apple. Will let you know the next episode.
  16. Vylen macrumors 65816

    Jun 3, 2010
    Sydney, Australia
    Well, given that 400mA near the heart can cause fibrillation and possible death... and that the USB specification states power draw at 500mA... it can do more than damage you if the hardware problem is serious.

    Of course, I could be lying (or mistaken, or over-exaggerating) and want to scare everyone :p
  17. chrono1081 macrumors 604


    Jan 26, 2008
    Isla Nublar
    This happens more frequently then most people realize.

    Unfortunately taking it to an apple store will do nothing because I bet they will not be able to reproduce it.

    It can be two things. ****** power in the building you are in, or lots of static. I'm guessing ****** power since you said it only happens with devices that are powered.

    If you plug them into a UPS (a good one, not just a power strip) this should eliminate the problem.

    This happened with most computers at my old work place and the only ones it didn't happen to (at least that I noticed) was the ones hooked to a UPS.

    Oh and you can get shocked, just slightly though. I got shocked on both USB and monitor (vga) cables at my old workplace.
  18. RedReplicant macrumors 6502a

    Mar 31, 2010
    This happens to me every time I touch the metal casing around the USB ports by accident with the USB device I am plugging in. Both my old i5 and every MBP I've owned.
  19. Thermonuclear macrumors 6502

    May 23, 2009
    The most likely cause is that there is some problem with externally powered equipment using an electrical ground that's different from the ground in use on the iMac. This could be the result of improperly grounded hardware, bad grounds, different grounds (of which one is bad), or bad external wiring.

    An experienced electrician can do a grounds and power test in under a minute for any mains socket. (You can too, with the right equipment.)

    Idea: Get a good brand-name power strip and plug ALL the equipment AND the iMac into that same strip. This test will eliminate many possible problem sources.
  20. MacBoobsPro macrumors 603


    Jan 10, 2006
    Slightly off topic but my ATV sparks like a frickin maniac when you try and plug in the power cord. I mean a real bright white flash and a loud pop. :cool:
  21. tpg macrumors regular

    Mar 19, 2010
    It's interesting that you say it only happens for powered devices - seems like there might be some kind of grounding issue. Is the imac plugged into the same distribution board as the external hard drive/whatever? Maybe try switching plugs to different sockets - one of them might have a dodgy ground connection
  22. Ocon macrumors newbie

    Jul 15, 2010
    This happens to all my powered USB's when plugging them in, I think nothing of it, it always happened on my old computer too
  23. wombatwod macrumors newbie

    Sep 9, 2010
    Sparks from Macbook usb ports

    Follow up to my earlier post.

    The problem has been seen and accepted by Apple and I am getting a replacement Macbook. I'm afraid most of what's said in these posts is not correct. It would seem to be a genuine problem with the computer (Apple told me they don't use the word 'problem', or 'fault', they say 'issue'). More spin for you. Anyway, the clue that it is a real problem is that when I plugged the USB devices in, or just got the spark when I brought the USB near the aluminium case, my remote monitor on the mini display port went out. When the technicians saw that happen Apple got more interested. It happens whether the USB device is powered or not, and whether the Macbook is powered or not.

    It can't be the 'capacitor effect' as it's only the USB case touching the Macbook case, not the actual pins themselves.

    What level of sparking to a metal case is acceptable? None obviously.
    By the way, a Macbook on battery is not earthed (grounded). What is the highest voltage inside it? Are metal cases a good idea? Hmmm?

    Tomorrow I have to sign 'legal stuff' from Apple. Wonder what that will be.
  24. wombatwod macrumors newbie

    Sep 9, 2010
    More sparks from Macbook USB ports

    Apple repair shop rang to say that the replacement Macbook,just received from Apple, has the same problem. What next! Could this be a design fault (sorry Apple - a design 'issue')?
  25. smetvid macrumors 6502

    Nov 1, 2009
    My iMac sparks a bit when I plug in a mini display port adpater to a vga monitor. It only does it if the tip of the adapter touches the metal case around the port when I fumble to plug it in. I have not been too concerned about it because it doesn't always do it.

    I do live in a pretty old apartment right now where the power may not be grounded so that could be the problem.

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