Issues with iMac recognizing external hard drive all of a sudden...

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Level 1

4 points

Issues with iMac recognizing external hard drive all of a sudden...

I've tried researching this issue for a couple of hours and have had no luck (or am not tech savvy enough to trust myself trying some of the recommended fixes from random websites).

Short(ish) version:

After contacting Apple Support in a panic because my computer (iMac, 24-inch, M1, 2021, 16GB) wouldn't boot up (black screen with colorful circle in upper left corner) and also wouldn't boot up in recovery mode. As she was having me try recovery mode again, I mentioned I have an external hard drive (Toshiba Canvio Flex 1TB) plugged in that I strictly use for Time Machine backup. She had me unplug that.... I was then able to boot up just fine and everything was working as it should.

Now I have tried Disk Utility in order to see what mess I could get into there...As long as this external hard drive is plugged in, Disk Utility just says "Loading disks". As soon as I unplug the hard drive, my internal hard drive information promptly displays.

Also, Time Machine says it hasn't backed up in a week or so and that it will back up when my external hard drive is connected (even when it is, in fact, connected).

I was able to get Disk Utility to show the external hard drive ONCE. I just left it on "Loading discs" and came back a while later to it showing. I have since tried this (for hours) and have no been successful. I have also tried a different port and a different cord.

Longer story details (not sure of their relevance):

The issue started when I went to use my scanner (Canon R40). I clicked the "Start" button and nothing happened. This has not been that unusual since I got this Mac. But I can always go into the "CaptureOneTouch" app on the computer and start scanning this way. However, this time I got an error message stating an issue with the drivers. Again, not that unusual with this scanner and Mac. Went to try downloading updated drivers and restart computer....the unable to reboot issue started.

Posted on Jun 21, 2024 1:19 PM

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Answer 1

Tesserax

Level 10

149,513 points

Jun 21, 2024 6:53 PM in response to TyP32

It appears from the report that your Mac may be using an external USB hub. Is this drive connected to this hub? If so, does this issue still occur when the drive is directly connected to your Mac?

Since this seems to be a problem no matter which Mac the drive is used with does appear to make it the culprit here. However, I suggest you follow BDAqua's advice on the next steps.

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Answer 2

Tesserax

Level 10

149,513 points

Jun 21, 2024 1:31 PM in response to TyP32

Based on your description of the issue, this external drive is certainly problematic and will need to be further diagnosed to determine what it is doing.

Toshiba makes very good drives, but any drive can fail ... but it shouldn't cause your Mac not to be able to boot up properly.

What I suggest, at this point, is to run an EtreCheck report, and optionally, post it here if you need assistance with interpreting its results. EtreCheck is a diagnostics tool, created by a valued forum member, that greatly aides in troubleshooting difficult Mac problems and may help us uncover the cause(s) of the one your Mac is having. There is a free version for you to try.

Since this drive appears to cause your Mac not to boot up properly, please keep it detached when running EtreCheck. Also, have you tried using this drive on another Mac? If you don't have another one, maybe a friend or relative can help you out?

Ref: Using EtreCheck to Troubleshoot Potential Mac Issues

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Answer 3

TyP32 Author

Level 1

4 points

Jun 21, 2024 1:46 PM in response to Tesserax

Thanks for your reply.

I have done the EtreCheck before on a previous Mac, so I was familiar enough with that...I'll include the results.

I have not tried plugging the hard drive into another Mac yet, as I was kind of dreading it. I have my previous one that I upgraded from because I didn't know what I was purchasing and it was painfully slow...which is the reason for the dread. I'll get busy on trying that though.

EtreCheck Results

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Answer 4

TyP32 Author

Level 1

4 points

Jun 21, 2024 2:50 PM in response to TyP32

Update:

Same issue on my other Mac. However, this time, it froze up on the shut down until I unplugged the hard drive and then continues with the restart. Wouldn’t boot up with the hard drive plugged in and nothing populates is Disk Utility until I unplug the hard drive.

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Answer 5

BDAqua

Level 10

240,875 points

Jun 21, 2024 4:40 PM in response to TyP32

What all is on this drive?

Is that drive used for backups or what?

Start with this if M1, M2, or M3 Mac...

On your Mac, choose Apple menu > Shut Down.

Wait for your Mac to shut down completely. A Mac is completely shut down when the screen is black and any lights (including in the Touch Bar) are off.

Press and hold the power button on your Mac until “Loading startup options” appears.

Select a volume.

Press and hold the Shift key, then click Continue in Safe Mode.

The computer restarts automatically. When the login window appears, you should see “Safe Boot” in the menu bar.

Does the problem occur in Safe Mode?

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Answer 6

TyP32 Author

Level 1

4 points

Jun 22, 2024 8:53 AM in response to BDAqua

I only use this drive for my Time Machine backup. Nothing I’m afraid of losing on it as it’s all on my Mac. Just would like to continue using it as a backup source without having to spend another $70 after only using this one a year and a half.

Alright, attempting to try this as I type…

First, with the hard drive plugged in, the Mac won’t fully shut down. Unplugged the drive, the Mac went completely off.

Next, with the drive plugged in, holding power button, starts up, only available option is “Options” and a loading circle under that. This is the same issue I had when I called Apple frantically afraid of an issue with the internal drive.

Unplug drive, loading circle immediately disappears and “Macintosh HD” option pops up.

I’ve now booted up in safe mode (verified that I was actually in safe mode via Google. Nope, didn’t even know how to do that on my own.) Plugged the drive in, tried to see if it would pull up in Disk Utility…still doing the same thing as before… “Loading disks” until unplugged then the Macintosh info appears.

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Answer 7

den.thed

Level 9

78,586 points

Jun 22, 2024 9:39 AM in response to TyP32

TyP32 wrote:

I only use this drive for my Time Machine backup. Nothing I’m afraid of losing on it as it’s all on my Mac. Just would like to continue using it as a backup source without having to spend another $70 after only using this one a year and a half.

That Toshiba External Drive has failed in some way. Could be the cable, the chip in the box or the drive.

Do not re-connect or use that failed Toshiba External Drive with your iMac.

What you need to do, is replace it with a more reliable Desktop External Drive and start new Time Machine on it.

For a good example, see > https://eshop.macsales.com/shop/owc-mercury-elite-pro

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Answer 8

Tesserax

Level 10

149,513 points

Jun 22, 2024 11:56 AM in response to TyP32

I concur with den.thed. I'm afraid that this drive is the issue and you will need to get a replacement.

You, of course, can get whatever brand you want, but I would suggest that you look at some of the OWC offerings.

Ref: https://www.owc.com/solutions/external-drives?drive-type=bus-powered-portable

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Answer 9

TyP32 Author

Level 1

4 points

Jun 22, 2024 12:57 PM in response to TyP32

That’s kind of what I figured. Thanks everyone for your help. I noticed on Toshiba's website that this drive has a 3 year warranty so I’ve contacted them regarding that as they also state they send a Visa card instead of a refurbished replacement.

I’ll go look into what OWC has to offer now. Thanks so much for the recommendations!

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Answer 10

TyP32 Author

Level 1

4 points

Jun 22, 2024 8:57 AM in response to Tesserax

I do have a USB hub that I use for random things and I guess I left it plugged in while running the check. I did not have the drive plugged into the hub though at any point.

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