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My external HD works on one computer and not another. why?

O

oxband

macrumors 6502
Original poster
Sep 10, 2009
333
4
So, I have this two year old 320GB toshiba external HD. It works with a USB cable.

When I plug it into my MBP (from 2009) it works. When I plug it into my MacBook from 2007, the light on it comes on but I cant' mount it. I've opened Disc Utility and I dont ever see it there.

How can I fix this? Any thoughts? I have used other portable external HD's on that MacBook so I'm not sure how to solve this problem.
 
It's possible that the MacBook does not provide enough power through USB to power the drive. Have you tried all the USB ports, sometimes one provides more power. If that doesn't work some hard drive companies have a Y cable that plugs into the hard drive and 2 USB ports to provide enough power, maybe Toshiba has one.
 
What file system is the external hard drive using? what OS is on each machine?
 
I'm running 10.6.8 on both computers. The external is Mac OS Extended.
 
Apologies for bringing this thread back from the dead, but I have the same problem.

It is Lacie Rugged USB drive. It worked fine on my iMac with 10.5 on it, until one day I plugged it and it didn't even show up in the finder. Disk Utility failed to find it also. Plugged it into other Macs with 10.5 and it worked fine. I then upgraded the iMac to 10.6 - no difference to the drive.

Upgraded to a Macbook Pro i5 with 10.6. Initially, fresh out the box, the drive worked. But, rather than use the MacBook Pro clean out of the box, I took the time machine backup (on another firewire Seagate drive) from my iMac with all my stuff on it, put the Macbook Pro into target disk mode and 'restored' everything from my iMac to the Macbook Pro. As soon as I did this the Macbook Pro stopped recognising the Lacie disk.

It is as if my iMac (and its backup image) has 'marked' the Lacie drive as bad and now refuses to mount it. This 'setting' has now transferred to the Macbook Pro. Short of reinstalling everything from scratch on the Macbook Pro can anything be done to get it to recognise the drive again?

It still works on other macs I've tried it on....

Strange...
 
"It's possible that the MacBook does not provide enough power through USB to power the drive. Have you tried all the USB ports, sometimes one provides more power. If that doesn't work some hard drive companies have a Y cable that plugs into the hard drive and 2 USB ports to provide enough power, maybe Toshiba has one."

The above reply is correct.

The older MacBook isn't supplying enough bus power to get the drive "up and running". It might seem to get "halfway there", but never completely spins up and mounts.

The solutions:
- Get a Y-cable (as mentioned in reply 2), and see if that works
- Get an external power source for the drive's enclosure (some drives have an input jack for external power, but others don't)
- Take the drive OUT of the enclosure, and use it with a USB/SATA "dock" such as these:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=usb+sata+dock&x=0&y=0
(many items shown, they all work the same, just pick one you like that's cheap)
 
As an Amazon Associate we earn from qualifying purchases.
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bodgerx said:
Apologies for bringing this thread back from the dead, but I have the same problem.

It is Lacie Rugged USB drive. It worked fine on my iMac with 10.5 on it, until one day I plugged it and it didn't even show up in the finder. Disk Utility failed to find it also. Plugged it into other Macs with 10.5 and it worked fine. I then upgraded the iMac to 10.6 - no difference to the drive.

Upgraded to a Macbook Pro i5 with 10.6. Initially, fresh out the box, the drive worked. But, rather than use the MacBook Pro clean out of the box, I took the time machine backup (on another firewire Seagate drive) from my iMac with all my stuff on it, put the Macbook Pro into target disk mode and 'restored' everything from my iMac to the Macbook Pro. As soon as I did this the Macbook Pro stopped recognising the Lacie disk.

It is as if my iMac (and its backup image) has 'marked' the Lacie drive as bad and now refuses to mount it. This 'setting' has now transferred to the Macbook Pro. Short of reinstalling everything from scratch on the Macbook Pro can anything be done to get it to recognise the drive again?

It still works on other macs I've tried it on....

Strange...
Click to expand...

Does it show any signs of life, like an activity light?
 
Fishrrman said:
"It's possible that the MacBook does not provide enough power through USB to power the drive. Have you tried all the USB ports, sometimes one provides more power. If that doesn't work some hard drive companies have a Y cable that plugs into the hard drive and 2 USB ports to provide enough power, maybe Toshiba has one."

The above reply is correct.

The older MacBook isn't supplying enough bus power to get the drive "up and running". It might seem to get "halfway there", but never completely spins up and mounts.

The solutions:
- Get a Y-cable (as mentioned in reply 2), and see if that works
- Get an external power source for the drive's enclosure (some drives have an input jack for external power, but others don't)
- Take the drive OUT of the enclosure, and use it with a USB/SATA "dock" such as these:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=usb+sata+dock&x=0&y=0
(many items shown, they all work the same, just pick one you like that's cheap)
Click to expand...

For me that doesn't apply. It is the iMac that it doesn't work on. It was fine to start with then all of a sudden it wouldn't mount.

Tried it an a range of other macs (both iMac and Macbook) and it works fine.

Changed to a new Macbook Pro, initially, it worked fine. As soon as I restored the system from my iMac to the new Macbook, then the Macbook stops recognising the drive - as if it has transferred this 'bad disk marker' knowledge about the drive across to the Macbook.

My guess is that if I start again with the Macbook, and wipe it, the drive will be fine. Don't want to do that though.

----------
DewGuy1999 said:
Does it show any signs of life, like an activity light?
Click to expand...

You can hear it whirring, so its powered. Physically, its fine. It works on every single PC/mac I've tried it on, except the iMac and then after i copied the system to the Macbook Pro.
 
As an Amazon Associate we earn from qualifying purchases.
bodgerx said:
For me that doesn't apply. It is the iMac that it doesn't work on. It was fine to start with then all of a sudden it wouldn't mount.

Tried it an a range of other macs (both iMac and Macbook) and it works fine.

Changed to a new Macbook Pro, initially, it worked fine. As soon as I restored the system from my iMac to the new Macbook, then the Macbook stops recognising the drive - as if it has transferred this 'bad disk marker' knowledge about the drive across to the Macbook.

My guess is that if I start again with the Macbook, and wipe it, the drive will be fine. Don't want to do that though.

----------



You can hear it whirring, so its powered. Physically, its fine. It works on every single PC/mac I've tried it on, except the iMac and then after i copied the system to the Macbook Pro.
Click to expand...

See if this discussion might be helpful:

'NO ACCESS' External Hard Drive in Ownership & Permissions
 
Anyone solve this problem?! I have it on a LaCie Rugged Mini. HELP. Sorry about the 9 year gap, but this is the only place where I found my problem. Seagate support wasn't very helpful
 
Last edited:
Luke Roberson said:
Anyone solve this problem?! I have it on a LaCie Rugged Mini. HELP. Sorry about the 9 year gap, but this is the only place where I found my problem. Seagate support wasn't very helpful
Click to expand...

first try something like this, which will narrow down whether you have sufficient power being delivered.

smile.amazon.com

HIGHROCK 30cm USB 2.0 a Power Enhancer Y 1 Female to 2 Male Data Charge Cable Extension Cord(1pc)

Note: The red marked Male cable is ONLY for charging; Another is Charging & Data Sync Cable 100% Brand New USB 2.0 A female to dual USB A male Y Power Enhancer cable. USB 2.0 A female to dual USB A male Y Power Enhancer cable Does one USB port not supply enough power for your USB device? This Syn...
smile.amazon.com
 
So which one? The HD has a Micro USB 3.0, and I have a Micro USB 3.0 to USB 3.0 cable. So the first link would connect to that original cable, and the second link takes the place of the original cable. And btw the hard drive works on the iMac I have, and it has worked before on my Macbook Pro for like a year and a half. don't know why it's not working now. I've reset the SMC and the PRAM.
 
Well, the cable came and didn't work. My hard drive worked for a year; it's so random that it wouldn't work now. I am 90% positive that if I did a factory reset on my MacBook Pro, then everything would be fine. Is there an application that only Activity Monitor shows or a file directory that tells the computer how or what to detect a USB presence? Is there anything that can be deleted? Is there anything that can be installed?
 
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