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WMU328

macrumors newbie
Original poster
Oct 27, 2017
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I am new to Mac, and yesterday I received a new Mac mini I7, with 8gb Ram. After receiving it yesterday and turning it on, worked on it for a few hours, then I turned it off last night. Then when I wanted to use it today, I turned it on, it showed the progress bar, got half way then the screen went black, and never did anything. So I turned it off and tried again, same thing. By the third time I was able to log in.

Then I went and ran some errands, came back a few hours later and turned it on, again I had to power on mini twice to get it to the login screen.

Since I am new to Mac, and new to the Mac mini, I am not sure if this is hardware related or software. Any help would be greatly appreciated!

Thanks
 
I am new to Mac, and yesterday I received a new Mac mini I7, with 8gb Ram. After receiving it yesterday and turning it on, worked on it for a few hours, then I turned it off last night. Then when I wanted to use it today, I turned it on, it showed the progress bar, got half way then the screen went black, and never did anything. So I turned it off and tried again, same thing. By the third time I was able to log in.

Then I went and ran some errands, came back a few hours later and turned it on, again I had to power on mini twice to get it to the login screen.

Since I am new to Mac, and new to the Mac mini, I am not sure if this is hardware related or software. Any help would be greatly appreciated!

Thanks

This is a bug with the mini in Mojave where the screen goes blank during boot. If you unplug the monitor cable, then plug it back in, you should get the screen to come up.

My mini has done it a few times, but not on a regular basis.
 
Did you enable FileVault during your initial setup? I've had a similar issue with the monitor on my new mini and after I disabled FileVault everything is fine.
 
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I am new to Mac, and yesterday I received a new Mac mini I7, with 8gb Ram. After receiving it yesterday and turning it on, worked on it for a few hours, then I turned it off last night. Then when I wanted to use it today, I turned it on, it showed the progress bar, got half way then the screen went black, and never did anything. So I turned it off and tried again, same thing. By the third time I was able to log in.

Then I went and ran some errands, came back a few hours later and turned it on, again I had to power on mini twice to get it to the login screen.

Since I am new to Mac, and new to the Mac mini, I am not sure if this is hardware related or software. Any help would be greatly appreciated!

Thanks

I believe Mojave 10.14.5 has re-introduced this bug. My 2018 i5 was working perfectly with Dell U2518D via HDMI. After updating to 10.14.5, the monitor will lose signal while booting up. For me, if I reselect the monitor input to Automatic and switch back to HDMI, the display gets the signal back.

Hope they fix it in the next update.
 
I also just bought a new Mac Mini 2018 (i5 model with eGPU though) and had a similar problem. After I had set it up. if I logged out or restarted etc. the loading bar would go 3/4 the way then just freeze showing a mouse in the corner and sometimes the login screen would flash in. Then it would load normally like every third reboot. I was so sure it was a weird hardware problem because it persisted through a clean install, but then reinstalling using Internet Recovery rather than the Recovery Partition fixed it (????).

Been working fine for three days now. First (Intel) Mac I've bought in like 7 years, not too impressed so far. Great machine, very fast, but I expect a little more reliability from Apple at $1500.
 
Thank you everyone for reporting back. I am using an HDMI cable to a simple 27" 1080p monitor. I wish I had looked at the Static Sleep issue before purchasing. I just submitted a report to apple with my issue. My next step will be to buy an adapter for the monitor to see if that is resolved, since it looks like it helped some. Thanks again!
 
Quick Update- I found that if I wake my monitor up before I turn on the MM, I have no issue with turning on the MM or waking from sleep.
 
I have this issue too. I actually though it was my Apple display acting up. Great, another problem with my MacMini :(
 
I have the same issue.

Mac mini 2018; 3.2GHz i7; 16GB RAM; 1TB SSD; Mojave 10.14.5. Purchased June 2019.

Issue: Immediately after boot, upon reaching the login screen there's a 50%+ chance the display disconnects, requiring me to reconnect the entire cable. The interesting part is I have zero issues if using dual-display setup. The issue only occurs when using a single display.

Further, I get "snow/static" (as described in the other thread) if using a much older Samsung display, but otherwise I get a simple disconnect if using a newer Samsung display.

I've tested every "trick" and configuration possible. 3 different displays, new/old display, Direct-HDMI, USB-C-to-HDMI, old/new HDMI cables, reset NVRAM, reset SMC, SingleUser Mode, Verbose Mode, reset display settings, change input detection, change AV/PC mode, adjust display resolution, confirm FileVault disabled, DetectDisplays button, clean OS reinstall.

The farthest I've gotten is 4 "good" boots in a row without an issue. Otherwise I get a "bad" boot seemingly every other boot. The only times it doesn't happen are if using a single display, when booting into Safe Mode, and when booting from an external HD.

I can see in the kernel log that the system is having some issue with the HDMI "hot plug detection." It almost seems like a timing issue. Perhaps using dual-display changes the conditions allowing it to seemingly work properly. Perhaps the issue is specific to certain types/brands of displays.

Although my dual-display setup seems perfect so far, it still has me very concerned that perhaps this is a permanent defect in my brand-new Mac mini, and has me considering if I need to save myself the grief and just return it. This Mac is meant to replace my 3rd MBP, which is the 3rd machine to have some fundamental defect (2 GPU defects and 1 battery defect.) Wondering if this is now the 4th defective unit. /rant

A user on the Apple forums indicated that he confirmed this is fixed in the Catalina beta, and also a version or two prior to Mojave 10.14.5. So that gives me some hope, but I'll believe it when I see it.

Question: Can anyone confirm that they are successfully using a single-display HDMI connection on a 2018 Mac mini running Mojave 10.14.5?
 
"A user on the Apple forums indicated that he confirmed this is fixed in the Catalina beta, and also a version or two prior to Mojave 10.14.5. So that gives me some hope, but I'll believe it when I see it."

Do you have a link to that source? =)
 
I have the same issue.

Mac mini 2018; 3.2GHz i7; 16GB RAM; 1TB SSD; Mojave 10.14.5. Purchased June 2019.

Issue: Immediately after boot, upon reaching the login screen there's a 50%+ chance the display disconnects, requiring me to reconnect the entire cable. The interesting part is I have zero issues if using dual-display setup. The issue only occurs when using a single display.

Further, I get "snow/static" (as described in the other thread) if using a much older Samsung display, but otherwise I get a simple disconnect if using a newer Samsung display.

I've tested every "trick" and configuration possible. 3 different displays, new/old display, Direct-HDMI, USB-C-to-HDMI, old/new HDMI cables, reset NVRAM, reset SMC, SingleUser Mode, Verbose Mode, reset display settings, change input detection, change AV/PC mode, adjust display resolution, confirm FileVault disabled, DetectDisplays button, clean OS reinstall.

The farthest I've gotten is 4 "good" boots in a row without an issue. Otherwise I get a "bad" boot seemingly every other boot. The only times it doesn't happen are if using a single display, when booting into Safe Mode, and when booting from an external HD.

I can see in the kernel log that the system is having some issue with the HDMI "hot plug detection." It almost seems like a timing issue. Perhaps using dual-display changes the conditions allowing it to seemingly work properly. Perhaps the issue is specific to certain types/brands of displays.

Although my dual-display setup seems perfect so far, it still has me very concerned that perhaps this is a permanent defect in my brand-new Mac mini, and has me considering if I need to save myself the grief and just return it. This Mac is meant to replace my 3rd MBP, which is the 3rd machine to have some fundamental defect (2 GPU defects and 1 battery defect.) Wondering if this is now the 4th defective unit. /rant

A user on the Apple forums indicated that he confirmed this is fixed in the Catalina beta, and also a version or two prior to Mojave 10.14.5. So that gives me some hope, but I'll believe it when I see it.

Question: Can anyone confirm that they are successfully using a single-display HDMI connection on a 2018 Mac mini running Mojave 10.14.5?

I bought my 2018 Mac Mini right after it’s release and never had an issue. But after upgrading to 10.14.5, I am facing exactly the same issue that your described. Luckily for me, if I select Automatic Detection on my monitor after it loses HDMI signal, it works again and I don’t have to unplug/plug the cable again. I am hoping Apple fixes this in 10.14.6 as selecting Automatic Input on the monitor every time on startup is annoying
 
I bought my 2018 Mac Mini right after it’s release and never had an issue. But after upgrading to 10.14.5, I am facing exactly the same issue that your described. Luckily for me, if I select Automatic Detection on my monitor after it loses HDMI signal, it works again and I don’t have to unplug/plug the cable again. I am hoping Apple fixes this in 10.14.6 as selecting Automatic Input on the monitor every time on startup is annoying

I didn't think to try changing the InputDetection as opposed to reconnecting the cable. I did try changing it from Automatic to Manual, thinking it'd be a permanent workaround.

Changing the InputDetection probably causes the monitor to reset, in which case it's equivalent to reconnecting the cable.

That does make it seem like it's simply a software issue and not a hardware defect. In that case, I'm less worried that I need to return the machine for a refund. Thanks for the insight.
 
Today I installed the latest Mojave Beta. No luck here either! Still the same issues! Thats it for me. I’m selling the machine. I have no faith that this will ever be solved. Same with all the audio problems I have. I’m going back to my old 2012 mini and Yosemite. Rock Solid ever since!
 
Today I installed the latest Mojave Beta. No luck here either! Still the same issues! Thats it for me. I’m selling the machine. I have no faith that this will ever be solved. Same with all the audio problems I have. I’m going back to my old 2012 mini and Yosemite. Rock Solid ever since!

I just installed Mojave 10.14.6 Public Beta on top of a fresh install of 10.14.5, on a partition. It definitely does appear to resolve my issues.

Single-display connected via USB-C-to-HDMI: 10 good boots in a row without issue. Dual-display connected via USB-C-to-HDMI: 10 good boots in a row without issue.

(Edit: I originally indicated that I was testing direct HDMI. I was not. I've only tested USB-C-to-HDMI.)

Sidenote: I also have an extended issue, which is a 3rd display connected via direct HDMI failing to connect on startup, and sometimes failing to connect upon wake. That extended issue doesn't appear to be resolved in the Beta.
 
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I just installed Mojave 10.14.6 Public Beta on top of a fresh install of 10.14.5, on a partition. It definitely does appear to resolve my issues.

Single-display connected via HDMI: 10 good boots in a row without issue. Dual-display connected via USB-C-to-HDMI: 10 good boots in a row without issue.

Sidenote: I also have an extended issue, which is a 3rd display connected via direct HDMI failing to connect on startup, and sometimes failing to connect upon wake. That extended issue doesn't appear to be resolved in the Beta.

That is promising! Thank you for the info. Right now I have a single display through HDMI, hoping the next release solves my issue! Thanks
 
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