iMac USB

Just wondered if anyone could shed light on a small problem I’m experiencing on my Intel iMac 24" (pre-aluminium).

The USB ports recognise USB sticks and printers and cameras etc etc. But they won’t recognise either of my external hard disk drives with USB 2 connections - one is an Iomega 250gb and the other a cheap Chinese enclosure of an old PC IDE laptop disk. Both of these mount instantly on both my G5 PowerPC and on my white Intel Macbook 13". The G5 PowerPC runs Tiger, the Macbook and iMac both run Snow Leopard.

But do as I might, these disks won’t mount on the iMac :frowning:

any ideas?..

Hugh


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Could it be a power issue? Those enclosures are often supplied with a
double-ended USB cable so that you can plug them into two sockets
simultaneously.

Roger

Roger Houghton
Bath, Somerset
email@hidden


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

You might try them in a USB hub – it might be the iMac is not providing
enough power to spin the HD drive mechanism.

hugh mailto:email@hidden
10 September 2012 14:49
Just wondered if anyone could shed light on a small problem I’m
experiencing on my Intel iMac 24" (pre-aluminium).

The USB ports recognise USB sticks and printers and cameras etc etc.
But they won’t recognise either of my external hard disk drives with
USB 2 connections - one is an Iomega 250gb and the other a cheap
Chinese enclosure of an old PC IDE laptop disk. Both of these mount
instantly on both my G5 PowerPC and on my white Intel Macbook 13". The
G5 PowerPC runs Tiger, the Macbook and iMac both run Snow Leopard.

But do as I might, these disks won’t mount on the iMac :frowning:

any ideas?..

Hugh


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options


Best wishes Peter

Peter Tucker . Oxford, UK . email@hidden


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

You might try them in a USB hub

A powered USB hub - not all are. But presumably these HDs have their own power supplies?

D


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

No the HDs dont have their own power supplies. I have a small unpowered hub which extends a single USB to 4xUSB. This works fine on the Power PC, also works fine on the iMac for most things.
But I mean, the Macbook running on its battery can mount these two drives using a single socket! (no need to plug both of the double lead bits in)…so I hardly think it’s a power problem. The iMac recognises and mounts most things, like USB sticks, cameras etc. But it won’t mount the HDs. The Macbook and G5 mount everything.


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

On 10 September 2012 19:52, hugh email@hidden wrote:

No the HDs dont have their own power supplies. I have a small unpowered hub which extends a single USB to 4xUSB. This works fine on the Power PC, also works fine on the iMac for most things.
But I mean, the Macbook running on its battery can mount these two drives using a single socket! (no need to plug both of the double lead bits in)…so I hardly think it’s a power problem. The iMac recognises and mounts most things, like USB sticks, cameras etc. But it won’t mount the HDs. The Macbook and G5 mount everything.

I wouldn’t expect them to work through an unpowered hub. Have you
tried using the double lead with one?

Roger Houghton
Bath, Somerset
email@hidden


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

On 10 September 2012 19:52, hugh email@hidden wrote:

No the HDs dont have their own power supplies. I have a small unpowered hub which extends a single USB to 4xUSB. This works fine on the Power PC, also works fine on the iMac for most things.
But I mean, the Macbook running on its battery can mount these two drives using a single socket! (no need to plug both of the double lead bits in)…so I hardly think it’s a power problem. The iMac recognises and mounts most things, like USB sticks, cameras etc. But it won’t mount the HDs. The Macbook and G5 mount everything.

I wouldn’t expect them to work through an unpowered hub. Have you
tried using the double lead with one?

Roger Houghton
Bath, Somerset
email@hidden


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

I hardly think it’s a power problem

Maybe not but a powered hub would help you find out.

D


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

The hub’s irrelevant - I’ve taken it out of the chain altogether, and even plugged directly into the iMac it won’t recognise the drives. Rebooted etc.etc


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Have you tried Disk First Aid on the Drives from another Mac to see if that shows up anything.

D


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Put it on the device that does see it, and see what format it has. Open up Utilities/Disk Utility.app and click on the disk name in the list at the left. See what the Partition Map Scheme attribute (bottom right) reads. If it says GUID, you won’t ever get it to mount on a PowerPC Mac. Not sure if that’s your issue here – didn’t pay close attention to the type of machine that’s failing – but that’s a possible cause of misery.

Walter

On Sep 10, 2012, at 3:26 PM, hugh wrote:

The hub’s irrelevant - I’ve taken it out of the chain altogether, and even plugged directly into the iMac it won’t recognise the drives. Rebooted etc.etc


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Dave: “Have you tried Disk First Aid on the Drives from another Mac” - I don’t quite follow you?..

Walter: they’re failing to mount on an Intel iMac. They mount quite happily on an intel Macbook (old white 13") and quite happily on a PowerPC G5.


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Have you tried Disk First Aid on the Drives from another Mac

I simply meant connect the drives to a Mac that does mount them and check them over with First Aid

D


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Do the drives show in the USB Device Tree with System Information.app on your Intel iMac?


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Hmmm, that’s interesting… I swapped things about on the back if the iMac and moved the keyboard to a different socket…and now the drives are recognised if plugged directly into the iMac (they weren’t recognised before).

Obviously the unpowered hub isn’t up to the job, so I’ll have to get a powered one. But a little swapping of socket use and a reboot has done the trick. Thanks for suggestions everyone.


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Try the double cable - that’s what it’s there for. I’ve had those sort
of HDs that would only work with one on some Macs even though they
were fine on others.

Roger Houghton
Bath, Somerset
email@hidden


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Hi, I’ve been following this thread with interest, but I’ve never heard of a double cable, Roger, could you or someone enlighten me please?

thanks
Trev

On 10 Sep 2012, at 22:07, Roger Houghton wrote:

Try the double cable - that’s what it’s there for. I’ve had those sort
of HDs that would only work with one on some Macs even though they
were fine on others.

Roger Houghton
Bath, Somerset
email@hidden


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Ha! It would be using too many ports, Roger…there aren’t enough to go round :wink:

I think the powered hub will have to make an entry!


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Hi Trev,
Some of these 2.5" drive enclosures require more power than a standard 5v USB socket can deliver so they ship with what looks like a Frankenstein cable with two USB plus on one end and a single mini USB plug on the other. Like this;

I’ve found that if you plug in a drive like this and it doesn’t mount or just clicks then chances are is that it is underpowered. Swapping a single cable for a double headed one will do the job although uses up all of your USB ports on a MacBook Pro. I’ve also had positive results using a good quality single cable rather than the cheaper ones a lot of these drives ship with.
Regards,
Tim.

On 11 Sep 2012, at 08:19, Trevor Reaveley wrote:

Hi, I’ve been following this thread with interest, but I’ve never heard of a double cable, Roger, could you or someone enlighten me please?


Experienced Freeway designer for hire - http://www.freewayactions.com


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options

Well, must admit I’ve never even seen one of those.

There again, I exist in a garden shed in Surrey so I’m easily astounded, confounded and befuddled, sometimes all at once.

thanks Tim
Trev

On 11 Sep 2012, at 10:34, Tim Plumb wrote:

Hi Trev,
Some of these 2.5" drive enclosures require more power than a standard 5v USB socket can deliver so they ship with what looks like a Frankenstein cable with two USB plus on one end and a single mini USB plug on the other. Like this;
Click

I’ve found that if you plug in a drive like this and it doesn’t mount or just clicks then chances are is that it is underpowered. Swapping a single cable for a double headed one will do the job although uses up all of your USB ports on a MacBook Pro. I’ve also had positive results using a good quality single cable rather than the cheaper ones a lot of these drives ship with.
Regards,
Tim.


offtopic mailing list
email@hidden
Update your subscriptions at:
http://freewaytalk.net/person/options