iMac crashes when powering off external Thunderbolt drive

Apple is working on a beta update of Yosemite. Let's hope it addresses this problem.

Seems that if you disconnect the thunderbolt cable before powering off the external drive, nothing happens. My solution for the time being :-)

you are right 🙂 i try . I have eject the HDD and i disconnect the cable . no panic .

it's a solution

and if i re connected the cable when the HDD is off nothing happened . The problem comes only when you switch off the HDD....

thank's

Same problem with my imac27, 10.10.2 and WD My Book Thunderbolt Duo 8TB. This is quite annoying!

Still not fixed with 10.10.2 😠.

Same issue here too - everything was fine until upgrade to Yosemite 10.10.2

I'm running MacBook Pro (Retina, 13-inch, Late 2013), 2.8 GHz Intel Corei7, with 16GB 1600 MHz DDR3

My external hard drive is a G Tech 4TB with Thunderbolt.

The ejection problem only occurs when connected via the Thunderbolt. When connected via the USB - everything works fine.

I have visited the Apple Store in Birmingham (UK) and their technicians, despite being very helpful and polite didn't have a solution! In fact they said they'd not seen it before. However they did create a record log with my serial number and sent it to Apple!

They suggested I booked my MB in for a fault finding check.

I went onto to explain that it seemed to be relevant to the Yosemite upgrade and it was then they said that there will soon be a 'bug fix' up date for Yosemite - but they didn't know what was going to be included in it.

Surely with all these similar problems Apple should realise that there is an issue with Yosemite 10.10.2 and they should be taking steps to rectify it.

Feedback sent to Apple on 19th March 2015 - highlighting the issue further.

I also directed them to this form topic and this thread in the hope that they see it is not an isolated incident and that it affects a number of different Thunderbolt external drives - but the common link seems to be the 10.10.2 Yosemite upgrade!

Fingers crossed

HA, have done this several times the past month....or more...

Hi,

Let's wait the next update 10.10.3, perhaps Apple will fix it.

Interesting. I get tiny sparks when inserting USB3 cables from two of my LaCie ext. HD's (3TB, 5TB).

Should I be concerned, and what can be done to rectify the sparks?

I found this on the web:

http://superuser.com/questions/148408/why-do-i-get-sparks-from-my-usb-connector- when-connecting-it-to-my-mac

Nothing conclusive though.

Thanks

Same thing here with thunderbolt cables and the Mac Pro (black) when pulling the cables. The external drives cannot be shut down without trouble, so they are in sleep but still connected. I get the impression the bonding of mac and external drives is very tight. They are linked in one circuit. Maybe that's why there is this problem of kernel panics when the external drives are shut down. It seems to be a hardware/firmware problem. I hope Apple comes up with a solution to this.

vanstar sydney wrote:

Interesting. I get tiny sparks when inserting USB3 cables from two of my LaCie ext. HD's (3TB, 5TB).

Should I be concerned, and what can be done to rectify the sparks?

I found this on the web:

http://superuser.com/questions/148408/why-do-i-get-sparks-from-my-usb-connector- when-connecting-it-to-my-mac

Nothing conclusive though.

Thanks

As I said, those sparks (with Thunderbolt cables though) once caused my iMac to shut itself off, go blank, and the power button was unresponsive for a short while. Maybe there's some degree of surge protection in there, but the motherboard might have also been fried by the voltage difference due to the ground loop.

I don't believe there's anything that can be done to suppress the sparks, they are side effects of electrical design. I think you should be concerned indeed. If you want to protect your costly computer and drives, and be on the safe side, do as I do and disconnect everything from AC power before connecting / disconnecting devices that each have their own AC power supply. You could also in addition depress power buttons while everything is disconnected from power, to make sure that internal capacitors are fully discharged and aren't keeping residual voltage.

Very interesting, again. My iMac i7 (late 2012) has been experiencing random shutdowns for the past few months.

I've tried everything, except a clean install of the OS 😕

Questions, questions ...

Re: "disconnect everything from AC power before connecting / disconnecting devices that each have their own AC power supply"

I shall see how it goes.

My iMac12,2 also crashes when I power down my thunderbolt hard drive. My workflow is to turn it on every few days to let Time machine write a backup, otherwise I leave the drive off to encourage longevity (if I am generating lots of data I leave it on).

So my quickest option is to eject it, then unplug the thunderbolt cable? I don't think so - I don't want to be forced to upgrade by frying my motherboard.

Come on Apple, rock solid hardware is not so rock solid when it has flaky drivers. Put a firmware engineer on this and it should be fixed in what, a couple of weeks? No firmware engineers available? Hire one.

Obviously no one from Apple is reading this thread, they probably expect their clients to solve their stupid problem. My iMac 27 died today when I unplugged a G-Tech thunderbolt drive like all cases mentioned above. It seems that in many cases their computers recovered. Mine did not. I have tried rebooting in every available mode, safe, command-option P-R, unplugging to reset smc, using the computer as a target from another computer, etc. To no avail. Contacted some IT engineers at my institution, the only suggestion was to wipe everything and start new!

When trying to reboot it only gets to half the status bar and it just freezes there.

Can I sue Apple? after all this is USA right? but big companies are insulated by the small type text that no one reads when installing software, since there is no option to NOT AGREE and still install it. That should be an option, don't you think.

I am a media teacher, in the middle of the semester, can Apple even imagine the frustration and hassle that Microsoft-style blunders like this inflict on their clients? Apple is indeed rapidly self destroying their base, time for a banana.