Q: External hard drive (USB connected to Mac mini) disconnects during usage
I have a 3TB hard drive (WD green) in a "miniStack MAX Media" external drive enclosure, connected to my Late 2012 Mac mini via USB.
I don't know when it started doing this, but I recently noticed it was unmounting even when it was in use; the error was:
Disk Not Ejected Properly
Eject "3TB" before disconnecting or turning it off.
I replaced the USB cable, and saw the same errors.
I moved the HDD to a different enclosure; same errors.
I swapped the HDD to a brand new 4TB WD blue; same errors.
So now I have a new drive in a new enclosure with a new cable, and I'm seeing the same "Disk Not Ejected Properly" messages.
(Incidentally disk utility showed both drives were fine when I ran First Aid.)
This leads me to assume the problem is with my Mac mini, which is running El Capitan and is fully up to date with O/S updates.
Any recommendations on next steps to investigate/resolve this problem?
Mac mini (Late 2012), OS X Yosemite (10.10.3), home
Posted on Jun 24, 2016 4:21 AM
- Try resetting the SMC and NVRAM/PRAM
Intel-based Macs: Resetting the System Management Controller (SMC)
https://support.apple.com/en-us/HT201295
About NVRAM and PRAM
https://support.apple.com/en-us/HT204063
- Try starting in Safe Mode
OS X: What is Safe Boot, Safe Mode?
https://support.apple.com/en-us/HT201262
- Boot to Recovery and repair the startup disk
OS X: About OS X Recovery - Apple Support
https://support.apple.com/en-us/HT201314
- If it is repairable reinstall the OSX
How to reinstall OS X on your Mac - Apple Support
https://support.apple.com/en-us/HT204904
- If you do not have a backup use disk utility to restore the internal disk to an external disk so you can try to recover data.
Then format the startup disk and do a fresh install of OSX
As a test yo can also try installing your current OSX version on an extern disk and see if the problem persists. If it does then that would indicate a hardware problem wit yor mac.
Posted on Jun 25, 2016 8:38 AM