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

Hi,

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.

Thanks,
Adam

 

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.


...

 

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

Thanks,
Adam

 

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.


...

 

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.

Thoughts?
Adam

 

Only that it's interesting. Evidently the power requirements are well within
spec. What brand/model is this external drive?

 

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

 

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.

http://tinyurl.com/36zxu

 

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...

 

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.

 

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

 

Evidently, in your case, the drive doesn't pull that much current, but
others could. They are just covering the bases.

 

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