15" SR MBP USB Power Problem

Discussion in 'MacBook Pro' started by Bearxor, Oct 15, 2007.

  1. Bearxor macrumors 6502a

    Jun 7, 2007
    Howdy all!

    I have a 15" MBP and am wanting to use an external hard drive on it. It's a 2.5" USB drive, completely powered off of USB. I had no problems with this enclosure on my Dell notebook on any of the USB ports. The MBP, OTOH, is a different story.

    Every time I plug it in to the left hand side USB port, the drive powers on, then clicks off after a few seconds. In the right hand side USB port, the drive works great.

    This is very irritating because I use a wired trackball and would like to keep the cord tidy, therefore short. Now I'm having to reroute the trackball to the left side of the notebook while plugging the HD in to the right.

    My question; is this normal? Anyone else experience similar situations? The main difference between these two ports, from what I can tell, is that the left port is a header wired off of the motherboard where the right side is surface mounted. Maybe that makes a difference?

    Thanks in advance for all thoughts!
  2. Trepex macrumors 6502a


    Apr 5, 2007
    Ottawa, Canada
    That is not normal... there must be something wrong with the header or USB controller itself. Do other devices all work correctly on the left side? It sounds like the trackball does at least?
  3. harijay macrumors newbie

    Jan 31, 2008
    power problems macbook pro 17"

    I have the same exact problem. I am running OS X 10.5.1

    My 2.5" drive works on the RHS usb port only.

  4. TheStu macrumors 65816

    Aug 20, 2006
    Carlisle, PA
    I think it has to do with the fact that the right side port is directly attached to the logic board and the left side port is separate from the logic board.
  5. yippy macrumors 68020


    Mar 14, 2004
    Chicago, IL
    Nope, this is normal. Even on my Powerbook the right side port can provide more power than the left. How often do you need two high-powered USB devices plugged in at the same time?

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