Not recognizing external hard drive

I have 2 500gb hard drives. Both worked fine on my mac book pro up until I plugged into my Mums PC to share some files with her.

Now my mac wont pick up either hard drive. I cant access any of the files and face re formatting and losing all the information.

Why dont Apple do something about this?

You made some mistake in connecting same to your PC, what you did after same who is to tell.

none of that is any cause of Apple Inc.

I had the same issue. Found out FINALLY that the LACIE usb needs to be plugged into the port in the back of my imac (not the keyboard, or other additional usb port device). Hope this helps someone out there...

elisafromlivermore wrote:

Found out FINALLY that the LACIE usb needs to be plugged into the port in the back of my imac.....not the keyboard

Yeah, that never would have worked.

If you're using it for your PC it may not be formatted for Mac use unless you previously formatted your drive to FAT 32 to be able to use it on both.

If not, then I would suggest saving the contents to your PC and then reformatting to FAT 32 and reinstalling the contents.

If you're not sure how to do this, here's a good link;

http://www.online-tech-tips.com/computer-tips/formatting-external-hard-drive-to- fat-32/

After searching the web for hours and trying everything I finally found the answer to this.

I have a MAC Book Pro and also have the WD Passport, it was working just the other day and now it wasn't. I could hear it working and see the white light on but it was NOT showing up in devices but WAS showing up in disc utility.

Here's what I did; With my WD Passport plugged in I went to;

FINDER

APPLICATIONS

DISC UTILITY

Click on the WD Passport (in My case it said 1TB WD My Passport) at the left hand side so it's highlighted

Then click on FIRST AID

in the middle section then at the bottom right hand side click on VERIFY DISC

This gave me some errors that needed to be fixed, and then I clicked on

REPAIR DISC and in a few minutes it was fixed.

Now, I don't know if this was a problem for you, but when I clicked below the 1TB WD My Passport where I named my passport "Modella2014" (you will have a different name obviously) in the bottom section it said MOUNT POINT "not mounted"

So I went back up to "Modella2014" and right clicked (on the mac track pad that's a 2 finger click) and

selected "Mount Modella2014" and in a few seconds that was mounted.

Hope this helps, feel free to share and save someone else the 4 hours it took me to figure this out. Now back to editing!

I have a LaCie 1TB USB 2.0 external HD. This drive mounts without hesitation on my most recent past version Mac Pro (USB 2.0 ports) and on my current version Mac Mini (USB 3.0 ports), yet it will not make an appearance on my 7 year old MacBook (USB 2.0), nor on my current version (Oct 2013) MacBook Pro (USB 3.0). When connecting to the 'desktop' systems, the drive's blue lamp lights and the HD spins up and there it is in the Finder. On the MacBooks - no blue lamps, no spin up, not even lised in system report USB tree. Thinking that USB power may be an issue (this unit is not bus powered; it has a 12 vdc power supply), I tried using a powered USB hub; no joy. I am currently using the drive as the backup (Time Machine) media for my new MBP (drive connected to MacMini - MBP via WiFi (Airport Express)). That works well, but I will soon change that arrangement - full system restoration could be problematic if the drive won't mount while physically connected to the MBP. I'll continue to watch for probable cause, and solutions, for this issue.

I’d verify/repair the drive with Disk Utility (or something better) first and then check the type of partition table used. I use GUID and never had a problem.

Are you using the same version of OS X across all systems?

I was having the same problem. My MBP would not recognize my disk, and no image was mounted on my desktop. I went into System preferences and noted that while the disk was recognized it was not 'available'. I verified the disk through disk utility to no avail. In the end I ended up having to delete my previous backups, and re-format the disk for use by Time Machine.

I am using a 2010 MacBook Pro hard drive scavenged from my old laptop, the logic board of which suffered water damage.

http://www.seagate.com/support/external-hard-drives/portable-hard-drives/goflex/ ntfs-driver-for-mac-os-master-dl/

go to the link and download the driver for seagate goflex harddrive users. i did this and finally my harddrive can be detected on mac.

I had a similar issue. I went into Disk Utilities -> Selected the HD -> and then clicked Verify Disk. Hope this helps

Someone please help -

I have the latest macbook pro retina display running on 10.9.2

My external hardrive just stopped being recognized today however when i go

apple logo > about this mac> More info> System Report> USB then im able to see it there

but not able to do anything with it ???

PLEASE HELP !!!1 STARTING TO HATE MACS now

Have you tested the USB port with another device?

Activating the disk worked for me!

After doing this, the Time Machin worked again

About once a year my 2012 27" iMac decides not to recognise my Seagate external 2TB HDD. It doesn't even show up in Disk Utility. This always works to get it back again:

1. Unplug external HDD from power and USB.

2. Restart Mac.

3. Plug HDD USB cable into Mac USB port.

4. Turn HDD power on.

5. Wait several anxious seconds.

6. Success!

It never works if you have the HDD already powered up when you plug it in to the Mac USB, so I suspect something to do with USB power is the issue.