USB problems

[alesmart]

Hallo everybody!

I own a 2013 MacMini with ElCapitan and 3 external WD MyBook drives: 2x3TB (photo, files, ecc...) and 1x6TB (TimeMachine)

It's some week (since I've connected the new 6Tb but maybe it's just a coincidence) they dont' work properly anymore: every "some" hours they disconnect/reconnect by themself or they semm to be active but actually they're read only or they don't show any file.....
If I deactivate them on disk utility they don't reactivate anymore
If I unplug them and reconnect (or reboot the machine) they work again, but if I reboot TimeMachine makes the full backup of one of the disk, as it doesn't recognize it anymore......

I've changed usbport, cable, hub, I've to connect just one at once.... nothing to do: it seems that the "usb feature" of my computer is unstable.....

Any suggestion?

Thanks in advance

ale

 

[Buggyflayer]

Try System Preferences/Energy Saver/ untick Put hard disks to sleep when possible

 

[alesmart]

tried, but unfortunately did not solved....

 

[Buggyflayer]

Probably won't help but equally it won't hurt to try resetting the NVRAM https://support.apple.com/en-us/HT204063

Does it still happen if you just have one of the WD's plugged directly into the MacMini with no hub etc?

Are the MacMini and the WD's plugged into the same mains strip?

 

[alesmart]

i've tryed to update to Sierra, to reset PRAM and SMC, to fix permissions.... no way!
before I format and reinstall everything from scratch is there something I could try?
thanks

 

[BrianBaughn]

You don't have that "WD Sync" software installed, do you?

 

[alesmart]

no, I just use TimeMachine

 

[Fishrrman]

If you're trying to back up one external (non boot) drive to another, I suggest that you use either CarbonCopyCloner or SuperDuper to do it -- not TM...

 

[Mr. Retrofire]

@alesmart:
See
https://forums.macrumors.com/threads/osx-10-11-3-and-usb-problems.1951759/#post-22560963
and
https://forums.macrumors.com/threads/osx-10-11-3-and-usb-problems.1951759/#post-22649617