install mac os from usb
I have installed an new hard drive (SSD) now the imac (2013) doesn't boot
iMac 27″, macOS 10.15
Question marked as
Only works on Intel Based Apple Computer <<
To perform this action will require booting from a Bootable Installer.
The Bootable Installer can Only be performed on an Apple Computer
This will have to be performed from a Qualifying Computer to run the version of macOS to be made on the Bootable Installer.
Example : Bootable Installer of Big Sur would have to be done on a computer that Qualifies to run Big Sur.
1 - Shutdown computer and disconnect all external drive Except the newly created Bootable Installer.
2- Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive.
3 - It will present options >> Disk Utilities >> View >> View ALL attached Drives.
4 - Choose the Upper Most Drive ( not the volumes indented and list below ).
5 - The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map. This applies to macOS 10.14 Mojave and above.
6 - Once that is done >> backup out of Disk Utilities and choose install macOS.
7 - Follow the prompts and it may automatically reboot several time.
8 - Upon a final reboot - Setup Assist will present with the newer version of macOS.
