MBP USB port power management

Discussion in 'MacBook Pro' started by mac000, Jan 16, 2007.

  1. mac000 macrumors 6502a

    Sep 6, 2005
    Does the MBP close of the second USB port if the first USB port is running a high powered device? I have a keyboard receiver in one of the ports, and the macbook pro is also connected via DVI to an external monitor running in clamshell mode. When i connect an external harddrive, Nothing, no mounting not recognized anywhere. The only way i was able to locate the drive (and loose all my data on the drive) was by disconnecting the DVI and other cables and using the macbook pro soley with the external hard drive without the monitor. what a mess,
  2. redeye be macrumors 65816

    redeye be

    Jan 27, 2005
    How do you lose data on a disk by simply plugging in/out?

    If you have problems with the USB ports you might want to try a Hardware test.
    Put in the DVD that came with your MBP reboot and press "D" (or "s" i keep forgetting which one) until you see a black screen.
    Run the tests.
  3. mkrishnan Moderator emeritus


    Jan 9, 2004
    Grand Rapids, MI, USA
    I'm pretty sure the two USB ports are running off the same bus -- meaning they share power.

    1) Are you doing this off battery power or with a power adapter for the Macbook?

    2) Why do you need a receiver for your keyboard? Isn't it compatible with the built-in bluetooth?

    3) As for the drive, I take it that it's one that runs off of bus power instead of having a power supply?

    Is this a setup that you carry around with you? Or can you just buy an inexpensive powered hub and keep the two USB devices on it?

    The DVI port shouldn't be a big issue in all of this... in clamshell mode the computer shouldn't be expending much more energy doing video than it is when it's open, if it's not in fact expending less.

    You lost me with this part. What does it mean to "loose" data? Are you saying that you lose the data (meaning the disk became corrupted), or are you saying that you gain access to it (meaning you mounted it)? It's certainly possible to lose data on an external disk if you unplug it without unmounting it, although it doesn't *always* happen. But I'm not sure how that has anything to do with the rest of what you're describing.
  4. mac000 thread starter macrumors 6502a

    Sep 6, 2005
    right i meant i lost the data but regardless. When i was able to mount the drive while the macbook was not in clamshell, i partioned it as mac os journaled GUID partion. Ejected it, turned off the drive, plugged it back in and it mounted fine. From there i connected my monitor again and ethernet cable, audio, and magsafe. My external monitor has 4 USB 2.0 connections so i connected the MBP to the monitor with the "B" type , then connected the external harddrive and keyboard receiver (its a MS keyboard, no bluetooth) to the monitor.

    I tried turning the hard drive on and it didnt mount, i tried connected it directly to the mbp while it in clamshell and it didnt mount either. So i'm lost now.

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