Boot external M1 iMac?

[Dlass]

So I want to boot to an external disk on my M1 24" iMac (Monterey). I read that I'm supposed to power down, and then hold down the power button to see the boot choices. I do that, and nothing happens. What am I doing wrong?

 

[Cory Cooper]

Hello and welcome.

Here is an article that may help: How to boot an Apple Silicon Mac from an external drive

C

 

[Dlass]

OK, the trick seems to be that when you shut down, you need to WAIT some 10-20 seconds before doing a Power-Boot (holding the power button down) restart. When you shut down, you'll notice that the screen goes black. BUT IT'S NOT SHUT DOWN! Several seconds after it goes black, the screen flickers again, and THEN goes black permanently. THEN it's really shut down, and Power-Boot will work, and you can get to Boot Options. I was trying to do a Power-Boot immediately after the screen went black. Holding the power button down too early doesn't do anything at all.

 

[Howard Brazee]

The first black isn't quite as black as the off black.

 

[TonyAguila]

I can probably count myself fortunate in that the Mac Studio has a power indicator LED on the front panel to indicate that it is completely shut down when it turns off. Depending on the peripherals you have connected to the Mac, especially in the case of external drives, it can take a minute or so for power down to happen.

 

[Cory Cooper]

Hi,

Also, you could press the Caps Lock key on the keyboard before powering down, as it should turn from green (on) to dark (off) when the iMac has shut down completely. Works on the Apple Magic Keyboards...Bluetooth wireless too.

C