Mac computer Status Indicator Light behaviour

Learn about various Status Indicator Light (SIL) behaviours and what they mean.

The Status Indicator Light (SIL) on Mac mini and Mac Pro has different patterns based on the state of your Mac. These patterns also occur on some MacBook, MacBook Pro, MacBook Air and iMac models, though not all Macs have an SIL. If you have a Mac Pro, learn about the status indicator light behaviour on Mac Pro (2019).

After you've pressed the power button

Every time you turn on your Mac, it performs various hardware checks. If the SIL flashes once or more after you've turned on the computer, and the pattern is repeated after a brief pause, there may be a hardware issue. To isolate the issue, run Apple Diagnostics.

During startup

When you press the power button to turn on the computer, the SIL also turns on. As the computer starts up, the SIL stays on until the processor (GPU) has initialised and the display turns on. When the GPU initialises correctly, the display turns on and the SIL turns off simultaneously. 

On Mac mini models from 2011 and newer, the SIL stays on when the computer is turned on.

During operation or display sleep

While the computer is operating, the SIL remains off. If the display turns off but the computer is still on, the SIL turns on and does not blink. It remains like this until the display turns back on, at which time the SIL turns off again.

On Mac mini models from 2011 and newer, the SIL remains on when the computer is operating. 

You can turn on Display Sleep by pressing Control-Shift-Eject. To change your Display Sleep settings, drag the "Turn display off after" slider in the Energy Saver or Battery pane of System Preferences.

During sleep

When your Mac sleeps, the SIL pulses on and off slowly. On Mac mini models introduced in 2018 or later, the SIL stays on when the computer is in sleep mode. You can customise your Mac's sleep behaviour in the Energy Saver or Battery pane of System Preferences.

On Mac notebook computers, if the battery is completely depleted and the computer goes into Safe Sleep, the SIL doesn't illuminate at all.

During shut down

When you choose the Shut Down command, macOS first turns off the GPU. This turns the display off. When the display turns off, the SIL turns on. During the few seconds of shutdown, but before power has been removed from the main logic board, the SIL stays on and will not blink.

When the computer is completely shut down, the SIL turns off.

Firmware recovery mode

If Mac mini (M1, 2020) is in firmware recovery mode, the status indicator light rapidly flashes amber three times, briefly flashes amber three times, then rapidly flashes amber three times. This sequence is repeated until the computer is turned off. You may need to revive your Mac mini. If you still need help, contact an Apple Authorised Service Provider.

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