Intel-based Mac: Startup sequence and error codes, symbols

The following is an overview of the startup sequence, error conditions, and behaviors for all Intel-based Macintosh systems.

Note that some newer Macintosh models only use tones to indicate error conditions. See this article for more information.

Power On Boot-ROM/RAM check is initialized
  • Black screen, power LED on - POST or BootROM failure
  • Flashing power LED once per second - bad RAM, no RAM
  • Three flashes, a pause, and three more flashes (occurs continuously) - marginal RAM
BootROM-EFI Boot chime
Boot EFI
  • Metallic Apple - found boot.efi
  • Circle with Slash - could not load boot.efi, or some other issue
  • Flashing globe - looking for booter/kernel on netboot server
  • Metallic Apple with spinning earth below - found booter/kernel on netboot server
  • Broken Folder that blinks - no bootable device has been found
kernel Grey screen with Metallic Apple and spinning gear
launchd Blue screen
loginwindow Login window appears
User Environment Setup The text "Logging in..." appears in login window along with a progress bar. Upon successful login, the Desktop and Dock appear.

Learn more about trouble shooting on Mac OS X's startup process.

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