Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Powered USB stopping iMac from booting up

Just upgraded to the latest version of Big Sur (11.4). Since the upgrade, I can no longer boot up my iMac with my powered USB hub connected to the iMac. To get the iMac to go beyond displaying the Apple logo, I have to disconnect the hub from the iMac, boot the machine and the plug in the powered USB hub which works fine. I had no issues with the previous versions of Big Sur.


Does anyone know how to fix this issue?

thanks

Robert

iMac 27″, macOS 11.4

Posted on May 28, 2021 1:09 AM

Reply
Question marked as Top-ranking reply

Posted on May 28, 2021 9:46 AM

That is an odd problem. I would first try restarting the computer in the Safe Mode. With the hub disconnected. Press the shift key at startup. This can take up to ten minutes, so be patient. During the process the operating system is fixing things and cleaning its caches. Then reconnect the hub and restart normally to see what happens. I have a question for you. Have you tried starting up with the hub connected, but with all devices disconnected? One of those devices may be the problem. If so, try restarting with the hub connected and only one device. Then repeat with another device added, and so on. This way you can isolate the problem to a specific device and repost the results here. Let us know how it works.

Similar questions

2 replies
Question marked as Top-ranking reply

May 28, 2021 9:46 AM in response to smiro qualitas

That is an odd problem. I would first try restarting the computer in the Safe Mode. With the hub disconnected. Press the shift key at startup. This can take up to ten minutes, so be patient. During the process the operating system is fixing things and cleaning its caches. Then reconnect the hub and restart normally to see what happens. I have a question for you. Have you tried starting up with the hub connected, but with all devices disconnected? One of those devices may be the problem. If so, try restarting with the hub connected and only one device. Then repeat with another device added, and so on. This way you can isolate the problem to a specific device and repost the results here. Let us know how it works.

May 28, 2021 10:02 AM in response to smiro qualitas

What brand and model is the self powered USB hub? Try the following:


Boot into Safe Mode according to Start up your Mac in safe mode - Apple Support and see if the problem persists. Reboot normally and check again.


NOTE: Safe Mode boot can take up to 10 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files




Powered USB stopping iMac from booting up

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.