MacBook Pro 2008 motherboard failed. Upon sending it to an Apple authorized repair center, they confirmed this. They gave me the laptop back so I could open 'er up and get the hard disk out, which I did. The hard disk should be undamaged.

However, upon plugging it into an external enclosure – and connecting the enclosure to a computer running Windows – there's power, but nothing seems to happen. I'm just powering over USB. I wouldn't expect the HDD to be dead as well as the motherboard.

Does the 2.5" SATA HDD from a 2008 MacBook Pro need extra power when connected in that way?

  • What is the exact make and model of the external enclosure you are using?
    – user9290
    Jul 23 '12 at 14:58
  • That, I cannot answer. It's one we just had lying around at work, and is unbranded. It just goes mini-USB to USB, and only a single USB cable so no extra power going to it.
    – Kezzer
    Jul 24 '12 at 7:51

What is the exact make and model of external enclosure you are using? Some of them require an external AC adaptor. Some of them come with a duplex (two-headed) USB cable and require that both of them be plugged in to powered USB sources to provide enough voltage to run the enclosure and the drive.

Of course it is possible that your hard drive itself is damaged. If that is the case, you will need to pay a lot of money to a specialty hard disk data recovery service.

Finally, do you not already have a Time Machine backup of your Mac's internal hard drive to an external disk drive? When this current situation is resolved, it would be wise to invest in an external backup system using Time Machine.


Have you tried this drive in a different external enclosure? until you do that, you can't rule out that it's the external enclosure's problem and not the drive's problem.

  • I backed up all my videos to an external HDD. I'm a software developer so all my other work is in version control, and I use Google docs for all my documents. The only thing that was really lost was pictures, as for some reason, I had re-backed up important stuff recently, and simply forgotten all the pictures!
    – Kezzer
    Jul 24 '12 at 7:37
  • But surely Windows will recognise a drive is plugged in? It doesn't need to understand the file system, but just recognise that it's plugged in. I checked device manager and it wasn't listed there, which I presumed it would be.
    – Kezzer
    Jul 24 '12 at 7:38
  • 1
    Oh, and this time, I've ordered a 2TB external drive and am now on a paid backup solution online, so my data will be in three places ;)
    – Kezzer
    Jul 24 '12 at 7:42

My understanding is that USB drives do require more voltage than that provided by a chassis/ enclosure. Often the enclosure has a power supply and that should work, but if it doesn't, you could get one at a Radio Shack or equivalent.

An alternative is this cheap rig from Other World Computing that allow you to connect and power many types of drives.

OWC - http://eshop.macsales.com/item/NewerTech/U3NVSPATA/

  • I have used a similar product and this is a great way to go if you need to get data off the drive.
    – jtreser
    Jul 23 '12 at 12:48
  • Hmm, well, I plugged it into a decent Windows system at work and the disk didn't pop up on the drives list when I booted up, so I presume it's a dead drive.
    – Kezzer
    Jul 23 '12 at 13:55
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    No, not necessarily. Since it's formatted for Mac HFS+, Windows will not recognize it under any circumstances.
    – user9290
    Jul 23 '12 at 15:08

No, it shouldn't. I use this enclosure for external drive work, but what I found is that the USB port you use is important. Connect up the cable, and use the furthest USB port away from you of the two (i.e. the one closer to the MiniDisplay Port). I discovered this when first trying to use my Lacie 500GB external for TM backups, it would mount and then dismount after a few seconds, which was incredibly annoying. I then tried swapping ports, and it has worked flawlessly ever since. I think I read somewhere that Apple underpowers one port or something.

*This is the case on my MBP mid-2010 anyway.

Hope this helps!

  • I'm using the very latest MBP with Retina Display, so I'd have hoped they figured out power issues. Going to try @Wheat Williams' advice today.
    – Kezzer
    Jul 24 '12 at 7:42
  • @GrahamPerrin I believe I read it in a review, I'm going to have a look for it now. Kezzer the enclosure I mentioned utilises a dual port USB cable. Using both usually works, provided I put the data port in the frontmost port and the power port in the further one. I'm afraid I can't help you with the rMBP however, not sure of their USB's power configurations. Good luck!
    – Ali
    Jul 24 '12 at 10:06
  • As the opening question has become Windows-oriented, there's now a separate question for the commentary on our Apple hardware: Why might one USB port be problematic on a MacBook Pro? Jul 25 '12 at 10:28

The problem is to do with the file system. Whilst I had mentioned in some comments that I had plugged it into a Windows machine, I should have mentioned this in the main post. I assumed that Windows would pick up there's a drive there, even if it couldn't read the files, but I misunderstood how file systems work.

To fix this, I simply installed MacDrive 9 (there's also HFSExplorer) and plugged the hard disk directly into my PSU on my main system at work, and lo, behold the data!. I was quite surprised. I will not make this mistake again, as it was written in the book of data "thou shalt back up thy data otherwise a mighty plague of death upon your magnetic storage!"

So remember, Windows just fails to recognise an HFS-formatted drive.

  • Hint: if you wish, mark your own answer as accepted. Jul 25 '12 at 3:59
  • Indeed I am aware, but you have to wait 18 hours to be able to accept your own answer. I'm still waiting :)
    – Kezzer
    Jul 25 '12 at 7:25
  • Ah! I needed that hint. I wonder whether the waiting period should be within the FAQ. Jul 25 '12 at 9:13

If its a 2.5" then it doesn't need external power . I can assure you that.

  • 1
    This is not always true. It depends on the power (current) that the USB port can supply and on the power demand of the hard disk drive. The power (current) one USB port can supply is assigned in 100mA increments called "unit loads.". Some devices, such as high-speed external disk drives, require more than 500 mA of current and therefore may have power issues if powered from just one USB 2.0 port. For example when USB hubs are attached to a bus powered hub it selves consumes some power, leaving less than 500 mA power for the USB devices attached to the bus powered hub.
    – Pro Backup
    Jul 24 '12 at 16:32
  • In my case, this is not true. We re-attempted to go over USB again yesterday, and it simply didn't work. Plugging it directly into the PSU worked fine. The other option is to have two USB cables going into a single USB cable, so one power, the other transfers data. We need to find the right cables to be able to do this though, as I need to go mini-USB => 2xUSB.
    – Kezzer
    Jul 25 '12 at 7:27
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    Using two to one USB cable is different from having external power. I stick to my answer, 2.5" SATA or IDE hard disks don't need external power.
    – iGameRam
    Jul 25 '12 at 7:31
  • Using two to one USB cables provides extra power external to the hard disk. So technically, yes, it does require additional power externally, even if it's via USB.
    – Kezzer
    Jul 25 '12 at 10:00

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