MBP Definite Design Flaw: left usb 2.0 port underpowered

Discussion in 'MacBook Pro' started by pufftissue, Nov 13, 2007.

  1. pufftissue macrumors regular

    Sep 9, 2006
    Just an fyi:

    The left usb 2.0 port doesn't power an external 2.5" hard drive.
    The right side does.

    I actually thought that my 2.5" disk was failing until I used another spare. Then I thought that it was my enclosure, so I bought another one of those.

    Then I ran across the thread and that states that basically the left usb 2.0 port isn't producing the 500 milli amp current.

    If someone can correct me....I'd appreciate it; otherwise my apple is going back because I expect it to do what my $700 Dell laptop can do.

    <a href="http://discussions.apple.com/message.jspa?messageID=5170578">usb port power problem</a>

  2. jamesarm97 macrumors 65816

    Sep 29, 2006
    I had a problem with my external drive. It kept making a clicking noise. Turned out it was because I used a standard 3' usb cable instead of the short 6" one that came with the drive.

    - James
  3. superleccy macrumors 6502a


    Oct 31, 2004
    That there big London
    Some drives need more power than others.

    I have a MBP (see sig). Both my Western Digital Passport drives (one 120Gb, one 160Gb) work bus-powered from either of my USB ports using the supplied cable, left or right. No problem.

    I also have an older Seagate bus-powered 100Gb drive. It doesn't work from any USB on my MBP, but Seagate must've pre-empted this because they supply the drive with a power-boosting Y-cable with two USB plugs... which would've been usable if the USB ports on my MBP were actually next to each other.

    The Seagate did work on my Girlfirend's Dell though with a "normal" cable.

    So yeah, it sucks, but it's not reason enough for me to switch back to Dell.

  4. Loge macrumors 68030


    Jun 24, 2004
    Both my left and right side USB ports work fine with my 2.5 inch Lacie drives. Mine is the 17 inch 2.33GHz model (not SR).
  5. pufftissue thread starter macrumors regular

    Sep 9, 2006

    I actually have two Fujitsu 120 gb hard drives, i.e., the ones that come with the Apple MBP...

    Both do not work on the left side, and on the right side for some reason they're both quitting during a file transfer, but randomly.

    Some guy on the apple discussion threads reported that he tried 8 MBP's and they all exhibited the same behavior. It could have been his hard drive.

    But...it shouldn't be this picky.

    It works every time on every computer that I've had. I back up to my 2.5" drive, so to have this being unreliable on what I consider a valid drive (the one the MBP is supplied with!) is a no-go for the entire MBP. Too bad, b/c after alot of hassles, I got the LG screen that is really good.
  6. theBB macrumors 68020


    Jan 3, 2006
    If your drive somehow requires more than the specifications, then it is possible one port can supplying above the spec, while the other one supplies just enough to meet them. Then, Apple would be within its rights to refuse to fix it. I don't know what the specs for current are on USB ports, but if you can find out and compare it with how much current your drive requires on average, during initial connection, during spin up etc. A bit impractical of course...

    Just to be sure, you are using the same cable on both ports, aren't you?
  7. chaos86 macrumors 65816


    Sep 11, 2003
    dude, dont troll. if you switched to a mac, you won't switch back just because you have to plug something into the right side of the computer instead of the left. thats ridiculous.
  8. amusiccale macrumors 6502

    Jun 5, 2007
    Well, I love my mac too, but with only 2 USB ports on my mbp, I want to know that both could serve whatever I need them to do, within spec.
  9. plumosa macrumors regular


    Mar 17, 2007
    maybe yours just is malfunctioning. I'd take it in and see what they can do.
  10. Bearxor macrumors 6502a

    Jun 7, 2007
    I posted a thread on this about a month or so back. No one really responded. This is a definite problem. An external enclosure that worked fine in a Dell won't start on the left USB port of a MBP.

    I'm thinking it's either the drive or the enclosure's board. I upgraded my MBP hard drive to a 250 by buying a WD 250GB external and then put my 120GB in the MBP in the enclosure and it works fine off of the left USB port.

    Still, it shouldn't be this picky. Theleft USB port is not hard wired on to the motherboard, its attached by jumper leads. I have a sneaking suspicion that perhaps Apple has split one of the USB controllers so that several devices are trying to run off of one connection. Like maybe the iSight or the Bluetooth adapter + the left USB port.

    It's very irritating if you're using a wired mouse like I am. Unless someone can point me in the direction of a bluetooth trackball :)
  11. nikiski macrumors regular

    Oct 30, 2007
    Hong Kong, or Surrey, BC, Canada
    Well, let me share my experience with this USB external hard drive power thing...

    I have 2 2.5" external hard drive enclosures, one of which is a USB2.0 with a "Y" USB cable that is about 6" in length, and the other is a multiple interface enclosure that features FireWire 800 and USB2.0 (Let's call them enclosure "A" and "B" respectively).

    Enclosure A has a 80GB Hitachi drive: Hitachi HTS541680J9SA00
    Enclosure B has a 160GB WD drive: WD1600BEVS-60RST0

    I did a few tests on a few computers and found the following results:

    Machine 1 - MacBookPro3,1/2.4/4GB/160/SD, Manufactured week 44 of year 2007.
    Machine 2 - IBM ThinkPad R60e, Core2Duo T5xxx (don't remember), 1GB Ram
    Machine 3 - Self-built Core2Duo Q6600 on Asus P5WDG2-WS Professional motherboard with 2GB of RAM, in a Antec P180 case, with Antec SmartPower 550W Power Supply.

    There are 2 USB ports on machine 1 (1R, 1L), 3 on machine 2 (2R, 1L), and... 8 on machine 3 (6B, 2F) plus 2 on the Dell 2007WFP monitor connected to the back USB port of the computer.


    Machine 1: Enclosure A works on every single port. Enclosure B only works on the USB port on the right (Does not turn on if plugged into the left USB port).

    Machine 2: Enclosure A and B works on all ports.

    Machine 3: Enclosure A works on all USB ports. Enclosure B does not work on the front USB ports. However, the monitor ports work.

    In this test I only used a regular 6" USB hi-speed certified cable, as the Y cable will cause the drive to work no matter what.

    Working is defined by the drive being powered on, and a large file (1GB) is copied over and then back.

    I can't draw a clean conclusion since the drives are different and the chips are different, however I do think that the WD drive draws quite a bit more current than the Hitachi drive. (More platters?)

    Looking at the USB specs, I can see the maximum current that a device can request is 500mA. And look at the WD drive spec I can see that the current it draws during read and write is 500mA. I'm thinking that the chip + drive may require power beyond the 500mA limit.

    In conclusion, use drives that draw less power. Or use FireWire if possible.
  12. popelife macrumors member

    Nov 3, 2006
    I have noticed a similar problem, but not with powering an external drive...

    I use some apps that need USB dongles, and I can't lose both USB ports to a dongle each, so I have both dongles plugged into a bus-powered Belkin hub.

    Plug it into the LH port, and one of the dongles won't fire up (they both have an on-board LED that shows they're getting power), and the apps don't detect the dongles. Yet plug the hub into the RH port and everything's fine.

    So yeah, there does seem to be a power issue with the left port. Don't call this guy a troll, there's definitely something up.

    It's kind of annoying that the hub itself contains a huge unnecessary LED that makes the whole hub glow blue... I suspect it's the power requirements of the hub itself that puts it over the edge.
  13. ale500 macrumors regular

    Jul 9, 2007
    Just one small question, have anyone bothered to check the power requirements of those drives ?... Each USB port is by specification able to provide 5V @ 500 mA, not more.Most external USB enclosures are just cheap and they do not provide an external means of power.

    My Original MB 80 GB disk, a Toshiba MK8034GSX is rated: 5V @ 1 A.
    I have an external enclosure that accepts external power supply, but the MB is able to power it without problems, but *It is out of specification* !. (It works because it does not need 1 A continuously, just for spin-up, maybe running from battery it will not work, I did not test it).

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