Previous 1 2 3 Next 110 Replies Latest reply: Nov 17, 2009 11:36 AM by woof1912
reinski Level 1 Level 1 (0 points)
I recently bought a 100 gig Maxtor Mini external hard drive and it's only being recognized in one of my USB ports (the one on the right next to the Firewire port). I'd really like to be able to have it hooked up to the other port so I don't have to keep switching out cables. Anybody have a similar problem or any ideas???
Thanks -

MacBook Pro, Mac OS X (10.4.9)
  • iVmichael Level 6 Level 6 (13,725 points)
    How is the drive powered ?

    You will most likely find it will mount OK if it has an external power source, not the MBP USB Bus supply.
  • reinski Level 1 Level 1 (0 points)
    The weird thing is that my Maxtor external drive works fine in the USB port on the right - but not on the left. I'm not using any external power source with it. I forgot to mention that the port in question works fine when I put in my little thumb drive. So it's not like the port is dead. Crazy.......
  • mortaineatmac Level 1 Level 1 (10 points)
    Does it mysteriously unmount the thumb drive from the left USB port periodically?

    I ask because I have a similar right/left USB port problem, and I'm trying to troubleshoot it. I think there is a very common, under-diagnosed problem with the left USB port on the MacBook Pros.
  • matchstick Level 1 Level 1 (35 points)
    I have a similar problem. My USB -> ATA adaptor for 2.5inch drives only works on the right USB port.
  • tamsam Level 1 Level 1 (0 points)
    Hi All,

    Good to know that I'm not the only one having an issue with the left USB port on a Macbook pro. My Logitech VX Revolution mouse dongle registers in the right usb port but not in the left. Other devices work in the left port.

    I have heard that apple have a standard speed range in which the usb ports have to be, the ports can be low or high in the range. I'm thinking that the left usb port on a few of the comps fall in the low end of the specified range and aren't fast enough or high powered enough for some devices.

    Does anyone have any thoughts on this?

    Thanks,

    Tam
  • Goldfish Level 2 Level 2 (355 points)
    I was helping client install a DJ type audio program the other day and in the instructions they stated very clearly that the left USB port should NOT be used on MacBook Pro to connect the controller.

    I didn't think much about it at the time but now that I've stumbled upon this thread it's obvious that there's a technical difference between these two ports that Apple is not openly disclosing.

    g
  • tamsam Level 1 Level 1 (0 points)
    I thought I'd try using my logitech mouse dongle in the left usb port when running windows through bootcamp. And what do you know, the **** thing started to work. However, when I moved my notebook it had a random windows error. After wriggling the dongle a little the mouse connected again and everything was good.

    I then tried the same approach in OSX, and that worked too! I don't know if this was anything to do with getting the port to work in windows first, but it seems to be working in OSX now. A little bit dodgy though 'cos I had to wriggle it around until it connected to the mouse. Something is definitely a bit funky with the left usb port, but it looks like it might be the connection and not the power output like I originally thought.
  • John Tull Level 1 Level 1 (10 points)
    That's what I'm guessing as well. I have 1.8" drive enclosure that I was convinced was a dud until I switched my keyboard to the left and the drive to the right. Voila! I just tried my wife's last generation G4, which is the same enclosure as my Macbook Pro for the most part, and it will not work on the left there either.

    Seems this is not a flaw, but a nasty little secret that is not so secret any longer.
  • JB100 Level 1 Level 1 (0 points)
    just bought a new 15" macbook pro and left hand USB port does not work with my ipod or card reader - powers them up but it does not read the data from the card reader nor does it recognise the ipod is docked! help Apple - I will call them tomorrow, it does sound like a hardware design fault of some kind, love the machine otherwise!

    jb
  • ivanoats Level 1 Level 1 (0 points)
    This is interesting, I seem to have this problem in my RIGHT port.
  • Urbahn Level 1 Level 1 (0 points)
    I have the same problem with a CompactFlash memory card. I connect the USB-reader to my iMac and/or my Macbook Pro and it will sometimes work, most often the computer will not recognize it. This happens with a 4GB Sandisk Extreme III CF card.

    If I put a 2GB card, both from Lexar and Sandisk in, the Macs recognize it right away.

    I guess Apple has a serious problem with its USB compatibility.
  • MAKsBookPro Level 1 Level 1 (0 points)
    I saw a problem the first time I connected my external HD to the left port - it did not mount and the port got disabled - not even a mouse worked in it. On re-booting, the port was re-activated, till I re-connected the HD. I seriously think the problem is that the left port is 12Mb/s and the right 480Mb/s, although the specs say 2 x 480. A look at the System Profiler seems to confirm this. If this is true, well!
  • DCApilot Level 1 Level 1 (25 points)
    Through previous USB power problems on my old Powerbook G4, I found out that Apple adhered to strict USB power design requirements. Because not all devices are necessarily designed with that power supply in mind, I found that my USB hard drive could not be powered right from the USB port. I had to purchase a PCMCIA USB Card that provided sufficient power. Needless to say, I'm glad the work around was available but it required carring more equipment to make the hard drive work.

    I wouldn't be surprised if this is the case with the "left" USB port as I have had the same issues. Devices that do not require a lot of power, such as media readers and USB flash drives, work just fine. Any device that requires more than just a little power, such as a hard drive or my Blackberry, do not work in that port. However, they work just fine in the "right" port. It sounds like a power issue more than a port issue.

    If any of the techies out there who have done some testing could confirm/deny this previously known limitation, we'd be very appreciative.
  • Sharp-man Level 1 Level 1 (55 points)
    Interestingly, the Developer Notes for the MacBook Pro are different for the current and previous generation models; I'm not sure why, other than maybe the Santa Rosa chipset in the current model is actually more capable in the USB department. The System Profiler on my 10/2006 MacBook Pro indicates that the USB bus power for each port (left and right) is 500mA.

    From the Developer Notes:

    *15-inch MacBook Pro Computer (June 2007)*

    The 15-inch MacBook Pro computer introduced in June 2007, based on the Intel Core 2 Duo, has an internal USB 2.0 controller built into the South Bridge with one Enhanced Host Controller Interface (EHCI) and four Universal Host Controller Interfaces (UHCI). The controller has a total of eight ports, five of which are available to support two external USB ports, the Bluetooth module, the IR receiver, and the built-in iSight camera. The other three ports are used for the internal keyboard/trackpad, the ExpressCard/34 interface, and one is not used.

    +*The eight USB ports comply with the Universal Serial Bus Specification 2.0. The USB register set complies with the EHCI and UHCI specifications.*+

    +*The USB ports support 500 mA at 5 V nominal for 2.5 W power per port and are compliant with the the Voltage Drop Budget section of the Universal Serial Bus Specification 2.0.*+



    *15-inch MacBook Pro (October 2006)*

    The 15-inch MacBook Pro computer introduced in October 2006, based on the Intel Core 2 Duo, has an internal USB 2.0 controller built into the South Bridge with one Enhanced Host Controller Interface (EHCI) and four Universal Host Controller Interfaces (UHCI). The controller has a total of eight ports, five of which are available to support two external USB ports, the Bluetooth module, the IR receiver, and the built-in iSight camera. The other three ports are used for the internal keyboard/trackpad, the ExpressCard/34 interface, and one is not used.

    +*The eight USB ports comply with the Universal Serial Bus Specification 2.0. The USB register set complies with the EHCI and UHCI specifications.*+

    From http://developer.apple.com/documentation/HardwareDrivers/Conceptual/HWTechUSB/index.html#//appleref/doc/uid/TP40003026 and http://developer.apple.com/documentation/HardwareDrivers/Conceptual/15inMacBookP ro_0610/index.html .
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