iMac restarts repeatedly when external drives are connected

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Level 1

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iMac restarts repeatedly when external drives are connected

My iMac (14,3) has started rebooting when any external drive is connected to any port at any time. It starts with a trackpad freeze, then a restart without any message. I've tried starting in Safe Mode and it still happens. No issues when no external drives are connected. I reinstalled the OS (Catalina) in the hopes that would fix the issue, but it did not. I'm starting to think it is not a software issue, but a hardware problem with the ports. A short, perhaps? Nothing seems loose.

Thank for the assistance.

Dani

iMac 21.5″, macOS 10.15

Posted on Jul 17, 2021 4:32 PM

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Answer 1

Top-ranking reply

rkaufmann87

Level 10

143,688 points

Jul 18, 2021 7:41 AM in response to Dani Wray

Please navigate to www.Etrecheck.com and download the free version of EtreCheck. Once you have you downloaded the app and installed it, please run the report and save it. This report will help us get a good idea what has been installed on your system and help us be able to diagnose what may be wrong.

When you have your report, you can attach it when you reply to this message and we can then review it and help you determine what is needed to get your system running well again.

For instructions on how to download your EtreCheck report and attach it to your reply to this message please click https://discussions.apple.com/docs/DOC-250000211

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Answer 2

SeaPapp

Level 7

26,486 points

Jul 18, 2021 4:07 AM in response to Dani Wray

Try resetting the SMC How to reset the SMC of your Mac - Apple Support

and NVRAM Reset NVRAM or PRAM on your Mac - Apple Support

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Answer 3

Dani Wray Author

Level 1

64 points

Jul 18, 2021 7:39 AM in response to SeaPapp

Thank you, SeaPapp. However, I did both yesterday and there was no subsequent change to the behavior of the machine. In total, I have done the following:

Tested each external drive with each port. I have 2 that use Firewire and 2 that use usb. I changed up the ports to see if I could identify I single problematic port, but all exhibited the same behaviors.
I reset the PRAM and the SMC. No change in behavior.
I restarted in Safe Mode. No change in behavior.
I turned off all login apps. No change in behavior.

I'm stumped. The iMac functions well without any external drives attached.

Dani

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Answer 4

rkaufmann87

Level 10

143,688 points

Jul 18, 2021 9:14 AM in response to Dani Wray

There are a large number of system modifications running in the background.
GlobalProtectExtension
daisydiskapp

Above are just few of the issues I noticed, I suspect there are more. To be honest and please accept my apology in advance for being blunt your system is a big mess. I would seriously consider doing an erase and install and starting over.

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Answer 5

Dani Wray Author

Level 1

64 points

Jul 18, 2021 3:21 PM in response to rkaufmann87

Thank you, rkaufmann87.

The new M1 iMac I have ordered should arrive in 3-4 weeks and I plan on wiping this ssd drive and setting it up for my grandkids to use for school. Hopefully this will fix the issue, but I'm still not convinced this is a software problem. I can't plug any external drive in without the computer restarting. I guess I'll find out when I do it.

Thanks, everybody.

Dani

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Answer 6

Dani Wray Author

Level 1

64 points

Jul 18, 2021 8:08 AM in response to rkaufmann87

EtreCheck Report

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iMac restarts repeatedly when external drives are connected

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