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USB3 external drives randomly ejecting

Since the 10.12.5 update, I have been experiencing random ejects of external USB3 drives.

This is occurring on a 2011 21" iMac (12,1)


Normally I have 2 of USB3 Segate powered external drives connected via a Belkin Thunderbolt 2 Express Dock and have had this setup running for a long time without any issues.

I have tested the drives connected directly to the computers USB2 ports and they continue to randomly eject.


I have connected the same drives to my late 2013 15" MBP (11,3) both directly and via the same Thunderbolt Dock with no issues.

I have also connected the same drives to the USB port of my Airport Express and they stay connected without any issues as well.


Has anyone else experienced a similar issue since the latest update or any suggestions in searching Console logs for example as to where I may expect to find any relevant error messages that may indicate whay these drives are being ejected?


Thanks in advance

A

Posted on May 25, 2017 6:00 AM

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Posted on May 26, 2017 5:48 AM

It's not a widespread problem, but when it occurs an SMC Reset often fixes it. I needed to do that once and it has not reappeared.


It also may be related to the specific hard disk drive manufacturer. The drive I was using was a Seagate 2 TB notebook drive in an cheap enclosure, and I found a small number of other users with that same drive for whom the SMC Reset also worked. Further complicating the matter is the fact it occurred with the initial version of Sierra, so if it was related to that Apple may have fixed it a long time ago.


I think the fan problem is unrelated. In any event that's probably a very simple fix. Its impeller might simply be obstructed by debris. Or, its connector isn't connected. It's very tiny.


Edit to ask: did you remove the optical drive when you added the SSD?

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Question marked as Top-ranking reply

May 26, 2017 5:48 AM in response to actionmarker

It's not a widespread problem, but when it occurs an SMC Reset often fixes it. I needed to do that once and it has not reappeared.


It also may be related to the specific hard disk drive manufacturer. The drive I was using was a Seagate 2 TB notebook drive in an cheap enclosure, and I found a small number of other users with that same drive for whom the SMC Reset also worked. Further complicating the matter is the fact it occurred with the initial version of Sierra, so if it was related to that Apple may have fixed it a long time ago.


I think the fan problem is unrelated. In any event that's probably a very simple fix. Its impeller might simply be obstructed by debris. Or, its connector isn't connected. It's very tiny.


Edit to ask: did you remove the optical drive when you added the SSD?

May 25, 2017 6:54 AM in response to actionmarker

You didn't mention if you were using Virtualbox or not, but the following relates to how I randomly experienced external USB 3.1 Gen 2 connected drive enclosure (2GB Toshiba p300) disconnects from a 2011 Mac mini — and how I fixed it.


I am running Windows 10 Creator as a Virtualbox 5.1.22 guest with same version guest additions installed. However, I had inadvertently added that aforementioned external drive (where my guest content resides) in the Windows 10 guest settings as an included USB device (optional USB module). According to the fine print in the Virtualbox documentation, that is a no-no. When I removed that external drive from previous settings USB device list, then all random disconnects ceased.

May 25, 2017 7:06 AM in response to VikingOSX

No, no Virtualbox running here.


I am currently running the Apple Hardware Test.

The basic test returned an error code 4MOT/4/40000002:0DD-0, searching indicates that this if a Fan Motor Failure for the optical drive(?).

Not sure how this would relate to USBs randomly ejecting.


I'm currently running the extended test to see if anything else shows.

May 25, 2017 8:07 AM in response to actionmarker

Everything you did so far points to a hardware fault. Hopefully an Apple Store will be able to duplicate it because intermittent failures never seem to appear when you would like them to.


Apple also has more extensive hardware testing ability.


Contact Support


Don't wait because at the moment, your iMac remains supported. It won't remain that way for much longer. Once Apple considers it "vintage" service will be at their discretion, leaving you with less attractive and more expensive options.

May 25, 2017 4:54 PM in response to John Galt

John Galt wrote:


AHT will not become unresponsive simply due to an inoperative exhaust fan. It should be fixed, but I doubt it is related to that.


AHT didn't become unresponsive but rather stopped with the fan fail report. This was when the progress bar was only about 50%. So I'm presuming that AHT stopped when it found this failure and I have no idea what else had not been tested at that point.


But I agree, the fan failure probably has little to to with the current USB issue.


Everything you did so far points to a hardware fault. Hopefully an Apple Store will be able to duplicate it because intermittent failures never seem to appear when you would like them to.


Apple also has more extensive hardware testing ability.


Contact Support


Don't wait because at the moment, your iMac remains supported. It won't remain that way for much longer. Once Apple considers it "vintage" service will be at their discretion, leaving you with less attractive and more expensive options.


As I said, I'll open it up and check for the fan motor cable is seated correctly. The only reason I'm thinking of doing this first, is that about 2 years ago, I added a SSD to this unit and created a fusion drive with the original HDD. There is a possibility that I moved or did not seat the cable properly back then and it has come loose over time. I'll then be able to check AHT again to see if it can complete the full test.


At the moment I'm more inclined to think the USB issue is related to the 10.12.5 update as it started occurring very soon after that was installed. But if it is, it doesn't seem that it is a wide spread issue as I'm not finding other chatter about it.


Edit: Another thought.... the externals were also originally connected via the Thunderbolt Dock, not directly to the USB ports. I didn't have any other peripherals connected to the Dock to see if the Thunderbolt connection was being dropped or just the attached USB.

Jun 3, 2017 7:46 AM in response to John Galt

Thanks for your comments.


After about a dozen SMC resets over a week or so, the issue appears to have settled and gone away. (fingers crossed)

I haven't had the chance to open the unit up to look into the fan issue yet, but's on my list of things to do.


No I left the optical drive in place (not that its ever used these days) and used a high temperature resistant double sided tape to fix the SSD to the back of it similar to this https://www.macfixit.com.au/ifixit-imac-intel-21-5-mid-2011-dual-hard-drive-inst allation-kit/

USB3 external drives randomly ejecting

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