Mac mini 2018 won't enter Sartup Manager

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Mac mini 2018 won't enter Sartup Manager

I recently acquired a 2018 Mac mini with the T2 chip. I bought it because it is the most recent Mac mini with the Intel chipset and it can, in theory, dual boot a windows mobile drive or a linux installation. I have Linux dual booting on a 2014 Mac mini and it works flawlessly. The primary reason for this is to run Homeseer, but I also like learning Linux. I was just hoping for a newer faster machine.

That being said, I can't get it to enter the Startup Manager via holding the option key. I've tried immediately after pressing start, waiting until the chime, and various times in between. I've reset the SMC and I have reset the NVRAM.

In case you are wondering, I have booted to Recovery and allowed external boot media in the Startup Security Utility. I have it set up with no security and no firmware password.

I thought maybe the firmware was corrupted and I performed a "Revive" procedure both with Apple Configurator and with a M1 MacBook Pro. That didn't work, so I also performed the "Restore" procedure and that seemed like it was going to be bricked, but it finally started back up and I got Sonoma loaded. It still won't enter the Startup Manager on boot.

So it has the up to date T2 firmware, updated Sonoma OS. I can plug in my external Windows 10 drive and it shows up as a boot option in Settings>General>Startup Disk and I can then reboot to the external drive. However it will not see a installation USB and it won't enter the Startup Manager as will the 2014 mini or any other Mac I have owned for that matter.

Posted on Dec 28, 2023 9:03 AM

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Answer 1

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MtnMac2 Author

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10 points

Dec 28, 2023 11:34 AM in response to Matti Haveri

So... I shut down, reset the SMC only, but this time held the power button for 10+ seconds with the power cord out. Plugged it back in, held option and then restarted.

It worked. Yay! 2 days of my life lost. I can't believe after all that, the revive, restore, etc and the SMC must have never fully reset.

I rebooted and was not as quick with the option button to see if it still worked, and it did. The chime was quicker, the apple logo quicker. It seems to work normally now. Thank you Matti!

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Answer 2

MtnMac2 Author

Level 1

10 points

Dec 28, 2023 10:23 PM in response to Matti Haveri

I did the SMC reset, this time holding the power button for 10+ seconds with it unplugged. I restarted it holding the option key and it worked as expected.

I rebooted it and waited a bit before pressing the option key and it still worked. So I'm assuming that with all the stuff I had previously done, the SMC never reset. I won't get those two days back, but I am grateful for the advise.

Thanks Matti!

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Answer 3

Dec 28, 2023 11:22 AM in response to MtnMac2

> The screen stays black the whole time. Not Apple logo, nothing.

FWIW I lost some hair for a similar issue when I my Mac mini 2018 was brand new a few years ago (when Mojave was current):

No matter what (SMC, PRAM resets etc), I could not Option-boot to the startup manager. Also when the Mac booted into Command-R Recovery mode or the macOS installer rebooted in Option-Command-R Internet Recovery mode, the display suddenly went black. Also (Shift) Safe Boot booted into a black screen. ...but then I noticed that that disconnecting and reconnecting the USB-C Thunderbolt 3 or HDMI cable revealed what was on the display and what user input was needed to continue.

After a few months later macOS 10.14.6 update and obviously its firmware update fixed that.

And somewhat later in Monterey booted only to a black screen after a routine SMC & PRAM reset. I borrowed a newish MacBook Pro and used Apple Configurator 2 to Revive, and when that did not fix it, to Restore the Mac mini but the problem persisted. This took me a few hours and it was getting dark outside ... and I then noticed that the screen was not completely black but it _very_ faintly showed Apple logo and then the spinning Internet Recovery globe. But even in a completely dark room I could not use the almost black user interface. Screen brightness did not respond to the now-wired Keyboard controls (I had also switched to a wired mouse by then). I then connected the Mac to a TV via HDMI, and there the display worked as expected. The Restore had wiped the SSD data and apparently also disabled external booting so I had to use the slow Internet Recovery (Shift-Option-Command-R) which AFAIR first asked me to activate the Mac. I erased the SSD device and then proceeded to the presented Monterey install (during the install the TV went without signal for about 10 min and I cancelled it and started over. This time I was somehow presented with Mojave install which also had 10 min no signal period but then completed in about 25 min). I hurriedly re-enabled external booting.

After that no such issues and Sonoma has been OK.

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Answer 4

Dec 28, 2023 10:45 AM in response to MtnMac2

Have you used a wired keyboard or connected Apple's Bluetooth keyboard via Lightning to the Mac's USB port? And disconnected all other unneeded peripherals?

Have you tried to shutdown, press-and-hold Option-key while pressing the Mac's power-up button, and keep holding down Option-key until the startup manager appears?

Can you access a bootable macOS installer USB drive and re-install latest Sonoma on top of the old install.

Or reformat the whole internal device first as FAT (MBR) and then as APFS (GUID) to nuke the partition maps, and do a clean install?

Try to again reset SMC and PRAM:

Choose Apple menu > Shut Down.

After your Mac shuts down, unplug the power cord.

Wait 15 seconds.

Plug the power cord back in.

Choose Apple menu > Shut Down.

After your Mac shuts down, press and hold its power button for 10 seconds.

Release the power button, then wait a few seconds.

Press the power button again to turn on your Mac.

Shut down your Mac, then turn it on and immediately press and hold these four keys together: Option, Command, P, and R. The Mac should chime another time, and then boot, then release the keys.

Then shut down, and try again Option-boot.

What firmware does the Mac have? With macOS 14.2.1 it should be:

System Firmware Version: 2020.61.1.0.0 (iBridge: 21.16.2057.0.0,0)

OS Loader Version: 580~1053

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Answer 5

MtnMac2 Author

Level 1

10 points

Dec 28, 2023 11:01 AM in response to Matti Haveri

I've done all that. Both a wired Logitech keyboard and the Magic Keyboard connected with a lightning cable.

I cannot access a Sonoma install USB created per the Apple directions. The Sonoma Version came from the Recover Reinstall after the whole thing was erased, Firmware, T2, everything.

I'll try the SMC with holding the start button while unplugged and holding the option prior to and during the startup.

When I hold the option key it neither enters the Startup Manager or boots to the login screen. From the behavior of the lights on the USB, it seems to go into a boot loop. The screen stays black the whole time. Not Apple logo, nothing.

Current firmware is:

Sonoma 14.2.1

System Firmware Version: 2020.61.1.0.0 (iBridge: 21.16.2057.0.0,0)

OS Loader Version: 580~1053

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Answer 6

Dec 28, 2023 11:15 PM in response to MtnMac2

Nice to hear you got it fixed.

BTW I have used VMware Fusion (free for personal use) to virtualize Windows and Linux. Works OK. Broadcom recently bought VMware and its future is uncertain so I a switch to Parallels might be needed.

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Mac mini 2018 won't enter Sartup Manager

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