Lightning bolt
The lightning bolt and USB sign appeared on my MacBook Pro during start up. What does that mean ? I can’t turn on my laptop.
MacBook Pro 13″, macOS 10.15
Question marked as
Hi,
If you're seeing what looks like a lightning bolt symbol on the screen of your Mac, then it appears it has been mistakingly booted into target disk mode. Simply restart your computer without any buttons held down, and your Mac should start up normally.
Transfer files between two Mac computers using target disk mode - Apple Support