Apple KB#HT2674: Intel-based Mac: Startup sequence and error codes, symbols

15 12 2011

This Apple KB article demystifies what those startup symbols mean and what can cause them to appear:

Startup Sequence stage	Event
Power On	Boot-ROM/RAM check is initialized
BootROM-POST	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.

all the cool kids are doing it