Portable HD Micro USB connections?

[noblues]

I have an Iomega portable HD and wanted to use a longer cable, so I bought a longer micro USB to normal USB cable, although it fits OK it doesn't work.

I have done the same with my Toshiba drive which works fine ...

Is their any obvious reason?

[FullOppositeRudder]

Through the haze of advancing years and long hours at the bar, I seem to recall that the USB "standard" has some limitation on the maximum length of cable between devices for reliable operation. I can't quote a figure, and I haven't the specifics to suggest whether it's a factor in your case.

I do know that my USB wireless internet device will not work with a 2 metre extension cable, but is OK with a 1 metre cable or shorter. It seems that some devices are fussy about this; your drive may be one of them.

Conversely I have operated one of my Canon printers with a 5 metre cable without any problems.

Substitution of known good cables of varying lengths may find a workable solution if you can swap with someone else who has a variety of cables to try. Puzzling, but all part of the experiment that is modern technology.

FoR

[srobarts]

The spec varies between USB1.1 and USB 2.
For USB 1.1 the max distance should be 3m. If you are using a hub the max distance does not increase.
For USB 2 the max distance is 5m. You can daisy chain hubs to reach a max distance of 30m.
Wikipedia has a good article on USB including cable lengths.
It may be a power issue. My USB disk enclosure has a separate power lead which I don't need for my disk but I know others who do.
Do you have other power consuming USB devices attached. Try disconnecting all other USB devices so the disk is the only one.

[bnt]

I'm thinking it's a power issue too. Different PCs have different USB powering capacities, and if the situation was already borderline, a longer cable could tip it over.

One 2.5" external enclosure I bought a few years ago came with a 2-plug USB cable: you could plug both in to draw current from two USB sockets on the computer, and it was really necessary with an old laptop I had.

[noblues]

Thanks for the replies and comments ...

I have even tried a generic 30cm one to no avail ...

Yes, the drive had a 2x USB plug altough it works with just one of those plugged in ...

When I use a generic lead the power light comes on, but its not recognised by the PC ...

[srobarts]

Have you looked on the Iomega website to see if there is anything in the support pages for you model that might help?
You could also post a query to their support team to see if they can add anything.
If you haven't already done so try with a different PC as well.
Apart from those you have exhausted my knowledge.
If you let me know the model of your drive I can check on a private support site I have access to.

The iomega site has this article which includes the following:
Do not...
1. Connect or disconnect any USB device while any USB drive is transferring information. Data loss will result!
2. Use any USB cable with your drive other than the cable that came with the drive.
3. Use USB extension cables with your drive. Data loss might result.
4. Disconnect your drive or unplug power to the drive when transferring information.
5. Connect more than two drives with USB connections to a single computer.

[Keef]

If you look at the spec for what goes down a USB cable, the max speed that can be achieved is impressive. Devices that are close to the max speed are not going to work with anything longer than their specified maximum. That would mean, in particular, hard drives, cellular dongles, WiFi and similar.

Stuff that isn't in a particular hurry, such as printers, mice, and cameras will be more forgiving.