I have a WD external usb3 hard disk. I'm having a similar problem as mentioned in number of posts, which also offer solutions I've exhaustively tried. But of course some poster will ask me to list them all. I"ve closed many, googled for ages, here's some tabs that were still open when I finally posted.
In my case, I plugged the HFS+ formatted drive into my Windows 7 box and installed HFSExplorer and the drive mounted right away on Windows and I was able to copy files from it. The drive isn't damaged.
Here's some other things I've tried:
- using system information to see the usb devices (the drive is NOT listed)
- swapping between 3 different known working USB cables
- trying the usb port on the left of my MBP and the usb port on the right of my MBP
- trying connecting USB hubs to the USB ports, verifying that these show in system information, THEN connecting the drive to those hubs
- Connecting the drive to another Mac (yep, works just fine. Read/Write. Disk Utility verify doesn't report any problems).
- Connecting drives other than this one to the MBP and confirming they work on both ports, behind hubs, and so on
this mac will not see this particular drive.