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Level 1

20 points

Mac mini 2018: no start up (terminates signal to monitor)

Brand new mac mini 2018 (3.6 GHz, 250 SSD) arrived with Mojave 14.0 (to replace my 2012 Mac mini). Set up went well and it worked as expected for 1 day. Then I upgraded to 14.1, which required restart. But from here on out, I was never able to complete a restart. The first 30 seconds were fine, it showed the apple and progress bar on the monitor. But after about 50% progress on the progress bar, the monitor went black and shut down: "no signal detected", even though the computer was still on. After an hour on the phone with Apple support, and going through all possible restart options (cmd-ctr-R, etc.), all of which lost signal to the monitor at about half way through restart, they recommended to exchange the machine.

A week later, the replacement arrived (3.6 GHz, 250 SSD), except that this time Mojave was already upgraded to 14.1 (as I found out later). Fresh out of the box, I was unable to complete a full startup. As before, the progress bar moved about 50%, then the monitor shut down: "no signal detected". Despite the blank monitor, I could hear the machine ask for "select language, press return for English language", so apparently the mini attempted to perform the initial setup, but I could not participate, because the monitor had lost the incoming signal and had switched to standby. Again I went through an hour of Apple support via phone, but no success. Whatever we tried, after 30 seconds of attempting to start the mini, the monitor went black and received no further signal from the mini.

Same day, I took the mini to the Genius Bar at an Apple store. They connected their own monitor, but as before, the signal was lost after 30 seconds of trying to start the mini. However, they were able to start the computer without problem from an external hard drive with High Sierra OS. However, going back to Mojave 14.1, it was not possible to complete a start of the mini without losing the signal to the monitor.

Conclusion: The suspicion is that 14.1 has a glitch with the video card that disconnects the monitor during startup. Sadly, I returned the machine for a refund, as I did not want to go through yet another exchange. I will wait and see whether others experience a similar problem. If yes, perhaps 14.1 indeed has a bug and requires fixing in this regard.

Mac mini, macOS Mojave (10.14.1)

Posted on Nov 30, 2018 9:53 PM

28 replies

Dec 28, 2018 5:25 PM in response to Amigamac

Same here.. Out of the box it worked perfectly.. afterwords it was a constant battle of getting it to power on. However, after plugging it into a 3rd monitor that was separate from my two alienware ones, it worked like a charm. I rebooted a few times, even shut down twice. No problems. It's now setup to an Asus 34", but the amount of grief this has given me i'm over it. I'm going to take it back tonight and just pay the difference for a MBP.

mrg4guy

Level 1

4 points

Dec 30, 2018 4:19 AM in response to Music-Music

Music-Music, thank you for the advice. The HDMI cable meets the recommendations on Intel's website, in fact, it's the cable that was bundled with the monitor. I will try a different HDMI cable that should also meet the recommendations just to rule out a bad cable.

I've tried the monitor with other computers and I have not had issues with the other computers, only the Mac Mini 2018.

I went to the apple store and they were not able to fix my issue but they had a different 4k LG display at the store that they connected over USB-C. We could not get the alternate display to show bad or similar behavior to my LG 27UK850 display. After 3 shutdown/reboots and multiple tests they concluded that the issue was with my display and that the Mac Mini was working fine.

Dec 30, 2018 6:24 AM in response to mrg4guy

Thank you. Two points;

1- It is not very clear that Mac Mini 2018 doesn't work with all the LG 27UK850 displays yet. However at least two users can confirm that it doesn't. I am not really sure how Apple's staff came to a conclusion that your LG 27UK850 display is faulty without checking it properly.

2- It would be super useful if users can confirm which displays work with Mac Mini 2018 without any issue? (except the ones that Apple recommend)

Jan 6, 2019 4:31 PM in response to Marcolop

Marcolop

i have exactly the same problem with a 2018 Mac mini 3.3ghz 512gb ssd 32gb ram. The machine starts up ok with the apple logo at 50% on my 2 year old 65 inch 4k lg monitor, then the monitor just goes blank. My computer guy can see that the machine is actually working through remote access and he has control over it remotely . But on my side I have black blank silent screen.

But a 10 year old 22 inch sharp monitor works fine and it's just mad. Apple help desk passed the buck to lg saying that it is a firmware issue. Yet the smart TV updates automatically and has the latest version of firmware. My old late 2011 Mac mini with high sierra has no problems with the lg screen .

The other issue of the mojave os is that the icon management system blocks the machine until you reboot. I have 1100 cd's and 1200 movies on external hd' s And the artwork on all of them has disappeared. If I try to reactivate the extensions the mini blocks itself and will only work after a reboot. Without the icons this machine is useless to me.

this machine is going back to its maker.!

jmbr0cks

Level 1

4 points

Jan 22, 2019 11:59 PM in response to Marcolop

I am also having issues with my new Mac Mini 2018 and the LG 27UK850. Everything was fine with my old Samsung monitor. I hooked up my new LG 27UK850 via USB-C and have trouble when booting from power off mode on Mac mini. After pressing the power button on my mini, the Apple Logo appears and loads halfway, then the screen flashes and it reboots into Password Recovery mode, I select Restart from the Apple menu and it then reboots into a grey screen with a "Software Update needed to boot to this disk" message. I tried the update but it would just download for a few minutes, reboot and no display output. I discovered that if I select Restart from the Apple menu instead of choosing the software update option, the Mini restarts normally to my login screen and functions normally. I can do a Restart and everything seems to load normally with the display working, but if I do a Shut Down, then boot from the power button, I have to do the whole process over. Mini came loaded with 10.14.2 and managed to upgrade to 10.14.3, but still having same issues with LG 27UK850. I hope they fix the problems with connecting to this monitor soon.

Jan 28, 2019 6:27 AM in response to lllaass

I'm having the same issue on my 2018 i7 Mac mini with an LG 27UK850-W. I've just been in contact with LG about this, and they are saying that we would need to get in contact with Apple directly as it's not typically an issue on their side.

I went ahead and filed a bug report at bugreport.apple.com

LG did mention that typically they wouldn't get in contact with Apple to investigate the issue unless they had an overwhelming customer response. So maybe if a few more of you can get in contact with LG here (I used web chat) https://www.lg.com/uk/support/contact/chat-email

then maybe we can get enough attention to the issue for LG to reach out to Apple to escalate

lllaass

Level 10

210,423 points

Jan 23, 2019 12:37 AM in response to jmbr0cks

Maybe the LG monitor needs an update. See:

2018 Mac Mini monitor wake from sleep and… - Apple Community

The LG app is LG Screen Manager and is available from the Mac App Store.

Amigamac

Level 1

8 points

Dec 23, 2018 1:12 AM in response to Amigamac

Here's the issue, it's not able to detect my monitor thru the DVI connections

Dec 10, 2018 12:28 PM in response to lllaass

Two hard drives are connected. I have an iMac and the Hub works okay. Thanks

Amigamac

Level 1

8 points

Dec 17, 2018 10:20 PM in response to Marcolop

Any solutions? My brand new MacMini 2018 boots up to a black screen no matter what. Is the only option to create a USB install and format back to 14.0?

Dec 28, 2018 5:08 AM in response to Amigamac

When external HD/SSD was connected to Mac Mini I was getting a blank screen on startup. However with my Sony TV (1080dpi) it was working as expected.

Jan 5, 2019 10:40 PM in response to Marc_2015

Here is more discussion at MacRumors

https://forums.macrumors.com/threads/officially-giving-up-on-the-mac-mini-2018-4k-monitor-dream.2155175/page-2

Mar 2, 2019 10:29 AM in response to SparkyMarky84

Also having the same issues.

Unable to boot at all with 14.1, just boot loops endlessly on 3 different monitors with 2-3 different configurations each.

Mac mini 2018: no start up (terminates signal to monitor)