External USB drive on laptops that don't require 2 ports

Discussion in 'Computer Information' started by Adam Steiner, Apr 20, 2004.

  1. Adam Steiner

    Adam Steiner Guest


    My cousin has a Dell Latitude D600 and an external hard drive. The drive
    requires that he plug in a second usb plug also, so that the drive can power
    up. My question is, is this an issue with the drive requiring more power
    than other drives, or as a general rule, does a laptop's USB port not supply
    sufficient power to operate an external hard drive.

    Adam Steiner, Apr 20, 2004
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  2. Adam Steiner

    Thor Guest

    Depending on the type of USB interface on a laptop, some do might be able to
    supply the full 500mA that a standard USB port supplies, and may be required
    to power an external 2.5" drive, and also operate the logic circuitry.

    Thor, Apr 20, 2004
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  3. Adam Steiner

    Adam Steiner Guest

    I guess I'll shoot an email off to Dell or try to find the tech specs on
    their site.

    Adam Steiner, Apr 20, 2004
  4. Adam Steiner

    Thor Guest

    if he's using XP, check the USB root hub entries in the device manager and
    see how much current the external drive is demanding, and how much is
    available on each port.

    Thor, Apr 20, 2004
  5. Adam Steiner

    Adam Steiner Guest

    Never knew you could see the power there...anyway this is what it says:
    Total power available'--500mA
    USB mass storage device 98mA
    5 port(s) available 0mA

    Whether one or both plugs are in, it says 5 ports available and the number
    of mA doesn't change.

    Adam Steiner, Apr 21, 2004
  6. Adam Steiner

    Thor Guest

    Only that it's interesting. Evidently the power requirements are well within
    spec. What brand/model is this external drive?
    Thor, Apr 21, 2004
  7. Adam Steiner

    Adam Steiner Guest

    Apparently it was a DIY job. He bought a Toshiba mk4026gax 40GB drive and
    a Y-252U hard drive enclosure from Tech-Top Development
    (http://www.tech-top.com.hk/product_detail.php?product_id=111). I just
    sent them an email to see if they know what the problem is and to get the
    specs on power usage...

    Adam Steiner, Apr 21, 2004
  8. Adam Steiner

    Thor Guest

    Yeah, the info on that page is rather sparse. I just bought a really cool
    item made by CablesToGo. It's a USB 2.0/IDE adapter. Basically, it's just an
    easier quick way to temporarily connect an IDE drive (CD/DVD/HDD) up to your
    USB 2.0 ports. Kind of like a USB harddrive enclosure without the actual
    enclosure, just the interface in a nice neat cable package, and a small
    power supply for the drive. Great for quickly connecting a customer's
    harddrive to my shop server to back up data, etc. before working on them. I
    used to have to leave the cover off the server so I could do stuff like
    that, but now I can just plug the thing into the drive's IDE connector, and
    the other end into my USB ports on the front of the server, and plug in the
    small switching power supply to power up the drive. My only complaint is
    that the molded-in USB cable is too short. With a USB extension cable, I
    would be able to connect the drives directly to my server without even
    removing them from customer's case while on the bench, in most situations.

    check it out.

    Thor, Apr 22, 2004
  9. Adam Steiner

    Adam Steiner Guest

    Oh man, where were you yesterday? I bought a ByteCC enclosure for HDDs for
    a little less than that. I assume it's hot swappable (which would make
    sense if it has a seperate power supply for the drive). Whats the power
    supply like? A regular three prong plug? Have you tried it out with a USB
    extension cable?

    This looks like a godsend...
    Adam Steiner, Apr 22, 2004
  10. Adam Steiner

    Thor Guest

    It's hot swappable. When it's connected to the harddrive, it acts just like
    any USB mass storage device as far as windows is concerned, and the USB
    cable can be plugged in, or unplugged from the USB port while the PC is
    running, and windows will automatically configure it accordingly. The power
    supply looks just like one of those self-contained transformer boxes that
    you get with most LCD flat panel monitors, or a laptop computer. The DC
    power cable terminates into the standard molex 4 pin connector for plugging
    into your harddrive or CD drive, etc, and the AC cord is the standard
    detachable 3 prong PC type. Any standard PC power power supply cord will
    plug into this thing. I haven't tried it with a USB extension cable yet, but
    I have no reason to assume it wouldn't work, as long as the extension is an
    adequately shielded USB 2.0 compliant cable. The thing also comes with a
    short 2" long IDE cable extension (just a short length of regular IDE ribbon
    cable with a female and male connector), which I assume is for situations
    where the adapter unit itself is too bulky to fit onto the harddrive's IDE
    connector in a tight space. The ribbon cable extension would allow you to
    connect the adapter to the drive from a sharp angle if necessary. If I had
    one other wish besides a longer USB cable, it would be for a small on/off
    switch on the power supply box for conveniently powering the drive up or
    down. All in all though, a very handy tool. The main caveat, or precaution
    is that since you can be potentially working with a naked harddrive that
    isn't mounted in any enclosure or case, obviously great care needs to be
    taken not to bump the drive while it's operating, or place it on things that
    may not be ESD safe.
    Thor, Apr 22, 2004
  11. Adam Steiner

    Adam Steiner Guest

    Sounds great. I'll probably pick one up as soon as I unload my enclosure on
    someone (only reason I bought it was everyone was coming to me to get data
    off their failing drives).

    On another note, Tech-Top got back to me and informed me that yes, on big
    enough hard drives the second USB port would be needed to supply more power.

    Adam Steiner, Apr 22, 2004
  12. Adam Steiner

    Thor Guest

    Evidently, in your case, the drive doesn't pull that much current, but
    others could. They are just covering the bases.
    Thor, Apr 22, 2004
  13. Adam Steiner

    Adam Steiner Guest

    I guess so. I know a friend of mine has a good 2.5" enclosure, I'll just
    ask him what he uses.
    Adam Steiner, Apr 23, 2004
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