Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

iMac external boot issues

K

KVH

macrumors member
Original poster
Jul 23, 2002
36
1
Wi
I'm having an odd external boot issue with a late 2013 iMac. The internal HD died so I picked up a Samsung T5 external SSD. That was about 2 years ago or so. Fast forward to about a month ago when after an update to Catalina, it stopped booting from the Samsung. Reformatting and trying to load a fresh install didn't work. The iMac could see it in the Startup Menu, but would not boot. I got an old external RAID drive I had to work. Thought maybe the T5 failed so I ordered a new OWC external SSD Envoy Pro ELEKTRON, it arrived today so I've been trying to get it to work with no luck. I even took it to my 2010 Mac Pro, loaded a fresh Mojave install and verified that it would boot from and it did. Took it to the iMac and would not boot. Startup Menu can see the drive but no luck booting from. Even installing a fresh Catalina install to the OWC wouldn't work. Somehow the install fails as when I boot from the RAID, it shows the SSD not having an OS installed.

At this moment I'm trying CCC with the drive to see if that will work. I've loaded OS's many times before with external drives and have never run into issues like this.

Thoughts?
 
Update..... CCC worked. I also unplugged all USB devices from the iMac after reading other threads on this issue. Maybe it was just that but either way, got it working.
 
  • Like
Reactions: geo88
Update part 2..... If you shutdown the iMac and then reboot it with any USB devices (Backup HD and Printer) plugged in, the iMac does not boot. The iMac only boots when only the new (maybe even the old) SSD is the only USB device plugged in.
 
A friend of mine has an iMac late 2013. It has USB 3.0 ports, a 1TB hard drive and runs Catalina. Is it possible to boot and work well from an external SSD? She considers to buy one, but only when there are no problems. I guess this iMac doesn't have Thunderbold 3 ports, so she has to boot from the USB 3.0 port.
 
It does work with the one caveat.... with this iMac, if you have to reboot the computer, only the SSD can be plugged in otherwise you get the recovery screen every time. Can't say that this will happen with your friends iMac, but that's how it is with this one.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back