My iMac will not turn on after software update..It almost loads up then alert shows up and then runs the start up again but does not start the computer. I have tried this many times and the computer shows the same response .
iMac 27″, macOS 10.13
See if this works...
Safe Boot from the HD, (holding Shift key down at startup), does the problem occur in Safe Mode?
If not...
1. Start up from macOS Recovery
To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following combinations on your keyboard. Command-R is generally recommended, especially if you never installed macOS Sierra 10.12.4 or later… https://support.apple.com/en-us/HT204904#notupdated
Command (⌘)-R
Install the latest macOS that was installed on your Mac.
Option-⌘-R
Upgrade to the latest macOS compatible with your Mac.
Shift-Option-⌘-R
Install the macOS that came with your Mac, or the closest version still available.
See if this works...
Safe Boot from the HD, (holding Shift key down at startup), does the problem occur in Safe Mode?
If not...
1. Start up from macOS Recovery
To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following combinations on your keyboard. Command-R is generally recommended, especially if you never installed macOS Sierra 10.12.4 or later… https://support.apple.com/en-us/HT204904#notupdated
Command (⌘)-R
Install the latest macOS that was installed on your Mac.
Option-⌘-R
Upgrade to the latest macOS compatible with your Mac.
Shift-Option-⌘-R
Install the macOS that came with your Mac, or the closest version still available.
Any luck?
iMac will turn on but during loading phase it shuts down. I’ve tried safe mode twice but same results
Hold alt key at startup, how long will it sit on the Boot Choice screen without crashing?
iMac 27" starts the software loading but does not load it completely.
