IMac doesn't recognise any USB external hard drives

2011 iMac running on OS X 10.7.5
1. I have tried 3 different hard drives now and none of them work on iMac but all work on Macbook Pro
2. Not appearing anywhere - evenin in Disc Utility
3. Tried to remove all other USB's in use and still no joy
4. Tried to turn computer off and remove power for 10 mins and still no joy.
5. The one I want it to work for is Seagate Backup Plus but like the others just doesn't see it.
Can anyone give any further advice?

Thanks BDAqua I tried your solution as I mentioned in point 4 or my initial discussion but this did not work.
I only have a USB do you think I should buy a firewire cable and try that?
My USB works for everything I've tried apart from portable hard discs.
The firewire bug link you sent is obviously for firewire issues so I assume I don't need to read this until I have tried a firewire cable?
What do you mean by this statement "If so, I suspect the AC PSU if it has one."?
I'm not technical so couldn't understand the acronyms or how this statment tied in with the previous instructions.
Thanks again for taking the time to help me

Similar Messages

  • My new 24in imac doesn't recognize my usb external hard drive- snow leopard

    i was attempting to do a new time machine back up on my new mac but it won't recognize the usb external hard drive (kaser 250gb). i used it frequently on my old g5 imac, no problems. i plugged the hard drive into my g4 ibook and it recognized it right away. i followed the apple tip of pulling the power plug out of the wall power socket and pulled all the usb cables out as well (i have the wireless keyboard). i let it rest for over 5 minutes and only plugged in my wacom stylus and usb external hard drive. still nothing. and it doesn't show either in disk utility. i also downloaded as per another thread the 3g ntfs system preference but to no avail. the only thing i can of doing is erase and reformat my external on my ibook, but i don't want to risk loosing the data without a back up.
    anything else i can try? (before i buy time capsule) thanks

    i just checked again by plugging the external into my ibook g4 and checked how it was formatted - mac os extended (journaled).
    Then the 3GFS software is not required at all.
    i have an idea, not sure if it will work and it will have to wait a couple days until i get my firewire back from a friend, but this is what i'm thinking: my intel imac has a 1tb hard drive. could i use target mode between my imac and ibook? with my ibook i'd attach the external hard drive, then using the firewire and target mode start it up. hoping that the ibook hard drive and the attached external hard drive would show on my intel mac for which i could copy over the external back ups onto my imac. once completed, i could erase and reformat the external on my ibook and then try again on my imac to see if it appears on my desktop. do you think this might work (even though it is correctly formatted already?)
    I use Target mode on a regular basis for mounting the internal drive on a Mac to transfer or salvage data. I don't know if you will be able to connect to an external drive on the Target computer. There's not usually any reason for this and I don't know if the Target Mode will enable the Logic board to deal with the USB ports and transfer data. I kinda doubt it, but other more experienced users can jump in here.
    I don't think the problem with your external drive is the format, since you've already checked it and it is already formatted for a Mac. Intel Mac's will mount drives formatted by a PPC Mac with no problems, unless your OS doesn't support the chipset in the USB case that connects to the drive. There are some USB drives that are known to not work well with SL but worked fine with Leopard.
    You can buy a cheap USB case (about $30) and move the drive from the old case to the new case, or buy a USB to IDE adaptor cable (about $20), or you can buy a larger external drive that will work on the iMac and use the G4 to transfer the date from the old drive to a new one. Or you can take both drives to a friend with a Mac and use Disk Utility to restore the USB drive to a partition on the Firewire drive. That doesn't fix the USB drive to work with your new Mac, but unless the vendor comes out with a firmware fix, I think that's a lost cause anyway.
    other than the above, i may just go buy a 1tb time capsule,
    I would not be getting a Time Capsule to back up a single computer. Wireless backups are a lot slower than FireWire or USB (of course, it's the initial backup that takes so much time). If you do have several Mac's that need a TM backup volume, then the Capsule can help you out. It is supported by Apple (and there are a lot of users here in the forums). I'm using a ReadyNAS device for network backups, but it is not supported by Apple, and I have to rely on NetGear for fixes if an OS update breaks my backup system.
    BTW, it's a good chance that a TC device will be able to see and mount your USB drive. The incompatible chipset problem with some drives seems to be limited to the USB drivers in SL which the TC is not running. That's why I said that a USB hub may also let you see your drive, the problem is there's no guarantee's...

  • HT1338 my mac pro doesn't see my usb external hard drive what can i do?

    I'm having a problem with my mac pro not see my usb external hard drive. Can someone tell me something I can do to get the mac tosee the external drive?
    Thank you in advance.
    George

    Open Disk Utility (Applications > Utilities) and check the sidebar. If it's in it, select it and format it unless you have files

  • I need to back up my imac running Tiger (no time machine) so that we can upgrade OS. It is set up for multiple accounts.  How do I capture all files in each account using newly purchased USB external hard drive?

    I need to back up my imac running Tiger (no time machine) so that we can upgrade OS. It is set up for multiple accounts.  How do I capture all files in each account using newly purchased USB external hard drive?  Thanks!

    Backup Software Recommendations
    Carbon Copy Cloner
    Data Backup
    Deja Vu
    SuperDuper!
    Synk Pro
    Tri-Backup
    Others may be found at VersionTracker or MacUpdate.
    Visit The XLab FAQs and read the FAQ on backup and restore.  Also read How to Back Up and Restore Your Files.
    Or you can simply use the Restore option of Disk Utility to clone the drive to the backup:
    Clone using Restore Option of Disk Utility
    Open Disk Utility from the Utilities folder.
    Select the destination volume from the left side list.
    Click on the Restore tab in the DU main window.
    Check the box labeled Erase destination.
    Select the destination volume from the left side list and drag it to the Destination entry field.
    Select the source volume from the left side list and drag it to the Source entry field.
    Double-check you got it right, then click on the Restore button.
    Destination means the external backup drive. Source means the internal startup drive.

  • USB external hard drive and thumb drive don't work any more...

    I have a dual 2GHz PowerPC G5...and i've been using my USB external hard drive and thumb drives for a year with no problems....but now when i plug them in, my mac does not see them...the lights on the external hard drive and thumb drives come on as normal but nothing else...it does this on all the USB ports(front and back) BUT my iPod, keyboard and mouse, and HP printer (that use the same USB ports) works fine....(also i'm running Mac OS X 10.5.2)....help....

    You can't transfer songs from iPod to computer using iTunes, except for songs that you purchased from the iTunes Store (you can also re-download them using the iTunes Store Purchased screen).  However, there are third-party methods and utilities that can transfer song files from iPod to computer.  If you do a Google search on something like "ipod transfer," you should get some links.
    Once the song files are on your computer, drag the files (or the folder containing the files) to the iTunes window, to add them to the iTunes library.

  • How do i repair or recover data from a corrupt USB external hard drive that does not show up on my Mac desktop or disk utility

    How do i repair or recover data from a corrupt USB external hard drive that does not show up on my Mac desktop or disk utility?
    Last night i was using my external hard drive, for some reason the folder just closed and i couldn't find it on my desktop.
    After googling solutions, i found it in the disk utilities, i clicked on the 'repair' button many times, but it said the 'error...' message.
    So i ejected it to try again, now when i connect the USB external hard drive it doesn't show up on my desktop or disk utilities.
    I really just want to either repair or recover the data on it because it literally has everything (documents, work files, photos etc) on it,
    I downloaded an application to recover my files but it needs the USB to at least show up.recognise it which mine doesn't.
    I know i should've backed it up on another USB, this definitely teaches me for next time to back up all my files.
    Are the files lost forever or can i recover them by going to a shop or using a software?

    Thank you for responding.
    This might sound stupid since i'm not really knowledgeable with Macs,
    but since all my files were moved from my mac computer to the external hard drive,
    is it possible to recover those files through my Mac - like recovering deleted files? 

  • Can no longer access USB external hard drive

    Hi - I am running OS X 10.8.4 on my iMac (21.5-inch, Late 2009), and have been using a La Cie USB  external hard drive for several years for my Time Machine backups without issues.  All of a sudden yesterday, the external hard drive disappeared from Finder and my Desktop,  and as a result, no more Time Machine backups  I rebooted both the external hard drive and iMac several times  and changed the USB cable but with no success.  Disk Utility and Time Machine cannot see the external hard drive but it does appear under System Information => USB (see below).  I connected it to my Windows 8 laptop. The Windows laptop can see the external hard drive under Disk Management as an uninitialized disk.  But I will not allow me to initialize it and therefore cannot acces it.
      Product ID:          0x0951
      Vendor ID:          0x059f  (LaCie)
      Version:           0.00
      Serial Number:          152D203380B6
      Speed:          Up to 480 Mb/sec
      Manufacturer:          LaCie
      Location ID:          0x24300000 / 4
      Current Available (mA):          500
      Current Required (mA):          2
    Any help to restore the external hard drive would be appreciated.
    Ron

    Thank you for your quick response.  Disk Utility does not see the hard drive.  Windows 8 does see it under Device Manager and says that it is working propoerly but it will not allow me to initialize it.   As indicated  to Lin Davis,  I'll buy a new external hard drive.

  • Need help with homemade usb external hard drive

    I got a usb external hard drive kit that you can put any hard drive into, and I have a 20gig western digital disk. I cant seem to get it to work on my gateway(333 mhz celeron) with windows 2000, but I am going to order a imac in 6 days. Do you think that the external hard drive would work on a newer computer like an imac? Also What jumper settings would I have to put it on? The current choices are "slave", "single or master", and "master with slave present". There are also 3 jumper settings that could be possible, but it is not labeled on the hard drive.
    thanks!

    Rob, check the instructions that should have come with your drive kit, or check the manufacturer's website. Normally an IDE drive would be jumpered as 'master' or 'cable select' if it's used in a drive kit. BTW, that setting remains totally inside the drive housing, it is not visible or meaningful to the computer via the USB connection.
    Whether or not your kit will work with a new iMac is hard to tell, esp. since you haven't been able to get it working so far. Have you checked to make sure whether or not you need to install a USB driver for your drive kit on your Gateway machine? (Win98 always requires USB drivers, WinXP rarely does, and I'm not sure about Win2K). For what it's worth, MACs rarely require special USB drivers.

  • IBook won't connect to USB External Hard Drives

    I'm having a very strange issue with my ibook.
    I have three external hard drives (two of the three can use usb and firewire). If I connect them with firewire they work fine. Same thing goes for usb flash drives and usb devices (mouse, keyboards, ect.), but if I connect a usb external hard drive it refuses to read it. It gets power but it will not appear on my mac .....
    Now, I don't know if this has anything to do with it but a few years ago I was dj'ing with one of the hard drives that uses usb and firewire (it was connect using usb at the time). Something happened and the hard drive just stopped working. I thought it crashed at first. Its a western digital and every dj I know who has had a western digital has had it crash on them. I took it home and hooked it up to my pc just to make sure it was dead and it ran fine. Matter of fact I can still use it on my mac, firewire only though. Now no matter what type of external hard drive it is, if I am using usb it refuses to load on my mac.
    Any ideas on why this would happen?
    Also, the other two hard drives are both verbatim

    The best idea I have is that the USB bus in your computer isn't supplying enough power to your devices. You could try picking up a powered USB hub and using that to see if that helps.
    Alternatively, reset the PRAM, as outlined here:
    http://support.apple.com/kb/ht1379
    and the PMU as outlined here:
    http://support.apple.com/kb/HT1431
    ~Lyssa

  • Mac not recognizing USB external hard drive

    My Mac OS X 10.5.8 isn't recognizing my Samsung USB external hard drive. The hard drive has already been formatted for a Mac (rather than PC). My computer has recognized the external hard drive before with no problems. I've used it on a campus computer to copy video files from a documentary I was filming, and I've also used it on another campus computer to copy video files from a multimedia piece. I still need these files, so having to erase my hard drive would be DEVASTATING. Now, my computer won't recognize my external hard drive, even when I have it plugged in before turning on my computer.
    When I go to Disk Utility, my mac recognizes it, but when I try to repair and verify it says that it failed.
    It's also not a problem with the external hard drive because I've plugged it into another computer and it is recognized on the other computer.
    What should I do?

    When I go to Disk Utility, my mac recognizes it, but when I try to repair and verify it says that it failed.
    Sounds like it's very badly damaged, and it may be too much to expect the data to still be intact. However, you can try repairing it with a more powerful utility, like [DiskWarrior|http://www.alsoft.com/DiskWarrior/index.html] or [TechTool Pro|http://www.micromat.com>. If neither of those can fix it, then your only options will be using a data recovery tool, such as [Data Rescue|http://www.prosofteng.com> or [File Salvage|http://subrosasoft.com/OSXSoftware/index.php?mainpage=product_info&productsid=1], or paying an expensive data recovery service to disassemble the drive and recover what they can.
    Of course, this would all have been avoided if you had backups of your data. In the future, you must have a minimum of three copies of any data you don't want to lose.

  • My HP Pavilian dv6910 stopped seeing my USB external hard drive

    My HP Pavilion dv6910 stopped seeing my USB external hard drive. Up until 2 weeks ago I have never had a problem with the laptop reading and writing to my Seagate 500gb hard drive. I have  2 other computers that have no trouble working with the external drive. I thought maybe the circuit board in the external drive case was bad so I bought another one. Same thing. The Vista home premium software will not open the drive. Oddly enough, the drive is seen by the hardware manager and I can get volume information but Windows Explorer does not see it at all.
    The laptop has 3 usb2  ports and I have tried them all with the same results. I have other usb devises that work just fine on all ports.
    I thought maybe the driver got messed up so I did an auto search to replace and was told the current driver is ok.
    I do have a program called Advanced System Care Pro that auto cleans the registry (as well as many other things) and it might have removed something it should not have but I am not sure.
    I use the external drive for all my backups so I need to get this problem resolved as soon as possible. Can anyone help we with this?

    I meant reinstalling the operating system.
     There's a repair disc, but it's generally to repair a corrupted boot protocols.
     I had a look around and I can't find any place to download it either.
     Just thought if something _ you could try doing a hard reset.
     Shut down, remove the battery and adapter, hold the power button for 30 seconds.
     Plug only the adapter back in and boot up.
     Try you hard drive again _ give it a minute.

  • Should I get a 2.0 or 3.0 USB external hard drive for my 2011 Macbook Pro? I need it to be compatible with the USB ports of both a PC and a Mac.

    Should I get a 2.0 or 3.0 USB external hard drive for my 2011 Macbook Pro? I need it to be compatible with the USB ports of both a PC and a Mac. I was thinking of getting a Seagate becuase apparently it is compatible with both systems, but I want to know which would be a better investment.

    Using USB 3 devices on Mac computers FAQ

  • Can I use a Usb external hard drive on my macbook pro?

    I have a new macbook pro and have tried to connect my usb external hard drive , it shows up on the home screen and i can view and read only i cannot save anything into the external hard drive can anyone help.

    Yes. You have to prep it for your Mac. Currently it's setup for Windows.
    Drive Partition and Format
    1. Open Disk Utility in your Utilities folder.
    2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
    3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Apply button and wait until the process has completed.
    4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
    5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.
    6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

  • Is it possible to hook a USB external hard drive to an iPad?.....the HD has video on it that I wanna watch on my iPad but don't wanna store it on iPad or iTunes....and way format does the video need to be in to watch on iPad?

    Is it possible to hook a USB external hard drive to an iPad?.....the HD has video on it that I wanna watch on my iPad but don't wanna store it on iPad or iTunes....and way format does the video need to be in to watch on iPad?

    There are some wireless external hard drives that can be used with the iPad.
    The Kingston Wi-Drive, which costs $50 for the 16 Gigabyte, and then $30 more for every 16 gigs more. It works by you turning it on and then accessing the files on it from an app that you download on your iDevice. You can access music, movies, and other stuff. No connections or anything, it works like a WiFi connection, you connect to it from the setting on the iPad under wireless networks.
    Then there is the Seagate GoFlex, which some would recommend over the Wi-Drive. But this one costs $199 and had 500 Gigabytes of storage. It works the sameway as the Kingston: no wires, runs over its wireless connection. You can actually fit up to 300 HD movies on it.
    Another option:
    Expand your iPad's storage capacity with HyperDrive
    http://www.macworld.com/article/1153935/hyperdrive.html
    On the road with a camera, an iPad, and a Hyperdrive
    http://www.macworld.com/article/1160231/ipadhyperdrive.html
    Pad2, the new iPad Supported Video Formats & Movie Formats
    H.264 video up to 1080p, 30 frames per second, High Profile level 4.1 with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats;
    MPEG-4 video up to 2.5 Mbps, 640 by 480 pixels, 30 frames per second, Simple Profile with AAC-LC audio up to 160 Kbps per channel, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats;
    Motion JPEG (M-JPEG) up to 35 Mbps, 1280 by 720 pixels, 30 frames per second, audio in ulaw, PCM stereo audio in .avi file format
     Cheers, Tom

  • Can I use a usb external hard drive larger than 2TB?  I have tried to use a 3TB but it shows up as 800GB.

    Can I use a usb external hard drive larger than 2TB?  I have tried to use a 3TB but it shows up as 800GB.  Even tred to reformat in disk utility but only shows as 800 gb as well.  It is a Seagate 3TB harddrive and enclosure.  Nothing on the Seagate site about it other than it says Mac os through 10.6 is supported  for larger than 2TB (might be old).

    You might have better luck in the Snow Leopard community. I'll ask the hosts to relocate your post.
    10.6 Snow Leopard

Maybe you are looking for