Hi and welcome to the WD community. Try to run a first aid on the drive and check to see if the drive has any problems. Also try to check the drive with the WD Drive Utilities for mac.
![Best portable external hard drive for mac Best portable external hard drive for mac](https://images.iskysoft.com/data-recovery-mac/hard-drive/format-external-hard-drive-05.png)
![Best external hard drive macbook Best external hard drive macbook](https://cdn.setapp.com/assets/3810c452fb11c48d55250fe56c71c055/static/new/blog-post/disk-utility-first-aid.png)
Okay, so, here’s the deal somebody unplugged these drives from my Mac with OUT ejecting them first. a 2 TB My Passport Pro (connected via Thunderbolt). a 2 TB My Book Studio (connected via Firewire 800 to Thunderbolt adapter).
a 2 TB My Book Studio (connected to the first My Book Studio via Firewire 800) so i restarted then re-plugged them back in. They DID/DO mount. But i went ahead & opened the Mac Disk Utility app to run First Aid as per many years of habit. I could do this for the My Book Studio’s, and they passed. I could NOT do this for the My Passport Pro; wouldn’t give me an option to do so. I read some time ago that this was a known issue with the My Passport Pro’s & El Capitan; the solution was to use their (Western Digital’s) WD Drive Utilities app for such things instead. So, i ran the tests on the My Passport Pro, & since it was there, also the 2 My Book Studio’s.
Sometimes the “Quick Test” would pass on a couple of them, but every time, the “Complete Test” fails on all of them. Now, that raises a couple questions. why (as the title of this thread says) would one utility pass & the other fail?.
where is the “repair” function in the WD Drive Utilities app? I don’t have any access to Windows or Linux, i only have Mac’s. In my searching i found an app that says it’ll give you the complete lowdown on a drive, so i ran the trial/demo for them. Attached is a screenshot of part of it. So i feel pretty confident that these drives are failing. So i guess what i really need to know is can i repair these with software or are they really dying?