Mac can’t find boot drive after restart, but does if turned off and then back on.

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Mac can’t find boot drive after restart, but does if turned off and then back on.

I recently installed Mac OS on a USB 3.0 external SSD, and have encountered an issue that I can’t seem to fix. I already tried disk utility and running first aid on the drive in question, but that hasn’t helped. The issue is if I reset the system, it will not boot up and displays a folder with a question mark in it. But if I power the system off and turn it back on, it boots from the external SSD with no issue. I was able to install the latest update, but had to power off the system manually twice to get the update installed. I can’t find an answer using google search, so I’m hopeful that someone on her can help me with this issue. Thanks in advance 🙂

Mac mini, macOS 10.15

Posted on Feb 12, 2020 7:37 PM

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Answer 1

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dustin157 Author

Level 1

8 points

Feb 15, 2020 7:15 PM in response to raina_b22

Thank you for the reply! The external drive is selected as the boot drive in System Preferences. The thing with my computer is that It will boot from the external when I turn the computer on, but will not reboot into the drive if I restart the computer. If I restart the system, it will just go to the empty folder with a question mark. When that happens, I’ll hold the power button to shut it off and then turn the mini back on. Then, it will recognize and boot into the external drive.

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Answer 2

raina_b22

Community Specialist

Feb 15, 2020 1:10 PM in response to dustin157

Hello dustin157,

Thanks for that info and for choosing the Apple Support Communities. If I understand correctly, you are unable to start up your Mac with macOS installed on an external drive as expected. To help with this, please make sure you're selecting the external hard drive in System Preferences or in the Startup Manager and here is more info:

How to select a different startup disk

Cheers!

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Answer 3

dustin157 Author

Level 1

8 points

Feb 16, 2020 6:30 PM in response to dustin157

I have found what was causing the issue, and was able to resolve it thankfully. I did have both my external ssd (the boot drive) and an external portable hdd (time machine) plugged in the back of the computer through the USB ports. What I did to fix the issue was disconnect the external hdd from the port on the computer, and hook it to a self-powered usb 3.0 hub instead. Now, my mini boots both from a cold boot and when the computer is restarted. I’m glad to figure this out on my own, since I didn’t find anything online about the issue I was having. I hope this helps someone else who may encounter this issue 🙂

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Mac can’t find boot drive after restart, but does if turned off and then back on.

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