My iMac is having trouble starting enough and I have this lightning bolt running around the screen. What does that mean? I’m
iMac 21.5″, macOS 12.6
Do you have that iMac connected to another Mac using a Thunderbolt cable?
I ask, because that sounds like it is trying to startup in Target Disk Mode.
see > Transfer files between two Mac computers using target disk mode - Apple Support
Hold the power button for 10 seconds or until it turns off.
Then try starting up in Safe Mode.
My iMac seems to be having trouble starting. I have this lightning bolt running around the screen. How do I fix that?
