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newimacuser 04-05-2014 11:32 AM

External HD not recognised
 
Hi all,
Does anyone know why my Toshiba EXT HD only works with my iMac when it is plugged in via a USB ext cable and not when it is plugged in directly?

caribiner23 04-05-2014 11:35 AM

Can you describe what you mean by "plugged in directly?"

newimacuser 04-05-2014 11:40 AM

Hi,
Plugged in directly meaning the USB lead that came with the external drive was plugged into a spare USB port on the back of my iMac and nothing works or is seen by the iMac,
so if I then unplug it from the mac and then i plug it into a USB extension cable it will work fine

bobtomay 04-05-2014 11:43 AM

If one cable works and one doesn't - the one that doesn't work would be a bad cable.

newimacuser 04-05-2014 11:49 AM

Thanks bobtomay but it is the same cable thad i am using to plug into the USB extension so if lead is bad it shouldn't work that way either?
It is strange that it will only work when plugged into the extension cable and not straight to the mac

bobtomay 04-05-2014 11:58 AM

"Extension cable"? Is this a powered hub or attached to a powered hub?

newimacuser 04-05-2014 12:06 PM

It is non powered, about 3 feet long with a USB plug on one end and a socket on the other

Slydude 04-05-2014 12:20 PM

I assume by now powered you mean it is not plugged into a powered hub? Could it be a cable similar to this one? If so, the cable may be providing additional power. There are a number of bus powered hard drives that do not play nicely with some Mac models due to power issues.

newimacuser 04-05-2014 12:53 PM

USB 2.0 Extension Cable

The External HDD is a Toshiba 500GB and it comes with a short USB lead attached to it.
When I plug this into a USB socket on my iMac nothing happens and it is nor recognised in any way.

If i then unplug the Toshiba HHD from the iMac and then plug it into a simple USB extension lead similar to this one
USB 2.0 Extension Cable

It works! the iMac recognises it and I am able to use it, format it and have time machine back up to it.
I can't understand that why a simple USB extension lead that only serves the purpose of basically moving a USB port to the end of a cable so that you don't have to look around the back of the computer to find it makes the drive work? The External HDD should work by plugging it straight to the USB port of the iMac with out the need to use an extension.

chscag 04-05-2014 03:43 PM

Quote:

The External HDD is a Toshiba 500GB and it comes with a short USB lead attached to it.
By "attached to it" I'm assuming it can't be removed?

I've never seen a Toshiba external hard drive that had a USB 2 lead permanently attached to it. Can you give us the model number?

newimacuser 04-06-2014 08:51 AM

Quote:

Originally Posted by chscag (Post 1576415)
By "attached to it" I'm assuming it can't be removed?

I've never seen a Toshiba external hard drive that had a USB 2 lead permanently attached to it. Can you give us the model number?

HI, Yes the drive has a USB cable that can be detached, although I never have.
The model number is: HDTB105EK3AA

chscag 04-06-2014 12:14 PM

I just looked up your model Toshiba external hard drive. It's a USB 3.0 hard drive and therefore needs to use the special USB 3 cable. USB 3 cables can be plugged into a USB 2 connector on your Mac, however, the end that attaches to the drive has to be the special USB 3 connector.

You keep referring to the drive as USB 2. If the model number you gave me above is correct the drive is definitely a USB 3 type. So I'm thoroughly confused as to what exactly you've been doing with a USB 2 extension cable?

Here's the advertisement of the drive from Amazon.com:

Toshiba HDTB105EK3AA 500GB Stor.E Basics USB 3.0 2.5 Inch External Hard Drive - Black

newimacuser 04-06-2014 01:22 PM

OK just to clarify,

The drive will only work when plugged into a USB extension cable, it will not work when i connect it without the USB extension cable.
The drive comes with a USB 3 connecting cable that plugs into the drive and then into the Mac, but using this method does not work.
To get the drive to work I use the same USB connecting cable that came with the drive and instead of plugging it directly into the mac, I have to use a USB extension cable and plug the drive into that and then plug the other end into the Mac. It will now work as normal.
So the USB 2 extension cable I only use to get the thing working, it should work without it but it doesn't

ferrarr 04-06-2014 01:43 PM

Quote:

Originally Posted by chscag (Post 1576557)

You keep referring to the drive as USB 2. If the model number you gave me above is correct the drive is definitely a USB 3 type. So I'm thoroughly confused as to what exactly you've been doing with a USB 2 extension cable?

OP never said it was USB 2, only stated it was USB. Posted a link to a USB 2 extension cable.

What model mac and OS are you using?

The only thing I can think of, is the connection on the iMac is tighter with the extension cable plugged in and not with the EHD cable plugged in (you would have to get another USB 3 cable to test this).

newimacuser 04-06-2014 02:13 PM

Hi all,
Just been down to my local computer store and tried my drive on a iMac display model and the same thing happens on that too, the guy at the store had a spare drive cable that i tried and that didn't work either so concluded it was a faulty Toshiba drive. He said it was weird and he had never seen this problem before.

My iMac is the 27inch model running Mavericks and it is about 3 weeks old.


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