2018 Mac Mini - monitor problems

It's a known issue being investigated by Apple's engineers. No known fix at the moment.

The firmware update fixed all my problems - yay!

Well, then, the software update... 14.4..

I am waiting for apple solution! Meantime to survive, I am keeping the macmini on (without using the stop).

contact apple support until they get it resolved you can not fix it

I'm trying random solutions, and it seems to me that disconnecting the current from macmini and monitors when I stop working, it helps to restart ok.

My problem was resolved by booting with the Apple one-to-three adapter as noted previously; what's odd is I unplugged that and the problem never returned.

I urge everyone with display problems on a 2018 Mac Mini to call/chat with Apple Support and open a ticket. They aren’t going to do squat unless we all complain. This forum doesn’t count.

Login a complaint with their customer support as well. Let them know about it. This needs to escalate.

OMG, I thought I was going nuts! I have two Mac mini's and two LG 4k monitors and I'm having the exact same problem with both of them. This is beyond frustrating. I'm going to try turning off the file vault for now and see if that will work for me also for the time being. Thanks for posting!

I have a similar problem. New mini 2018 with external OWC 6 tb3. For the first week or so of daily usage, the external drives work fine and a 30 cinema 2560x1600 plus Samsung 27 2560x1440 screens work fine, one via hdmi the other by usbc.

I normally put the mini to sleep at the end of the day.

Then I shut down for 3 weeks with a full shutdown.

Then I start up and only one monitor works, often flipping between the two, and the six drives in the external OWC 6 thunderbolt 3 disappear entirely. The drives and both monitors are seen via system report, but the drives to not appear in the finder and I cannot read write to them.

After many restarts and cable juggling, the OWC drives reappear and work, the usbc monitor works, and rather hdmi monitor flickers once every few minutes to either go into tiny resolution, turn off altogether for a few seconds, etc.

the drives are encrypted.

Owc reports no no known issues with their tb3 external box.

something is seriously wrong within the 14.2 and communications to monitors and external hard drives.

apple needs to fix this... or perhaps they will take back the Mac mini?

I also had several (very long) calls with Apple and LG, none of them was able to help me. I never used Filevault and did several clean installs of 10.14, all with the same result.

When I connect my monitor to my BlackMagic eGPU there is no screen at all. I can see my screen waking up when I switch on my Mini, then after a few seconds "no signal" and then "entering power saving mode". Pulling out the TB3 cable from the eGPU and reconnecting it again wakes up the monitor presenting my log in screen. Until macOS goes in to sleep mode. Waking it up gives me a distorted screen, out of sync and scaling etc.

So there is definitely something wrong with the (moment of loading) of the graphics drivers?

It is a shame that both Apple and LG are unable to solve this, as there are so many users having more or less similar issues and not only in this forum. Googling for this issue gives many hits, but no solution.

I agree with "toto654".

I am a very old Apple's customer from the '90 and I must say that I am quite disappointed:

When I switch on my old MacLC (sistem7!), it wants to work again romantically.

When I switch on my new Mac Mini (sistem 10.14.3!) one or two of my double monitors 4K want to sleep and I am forced in long time of random solutions to arrive at my files.

Now my personal survival strategy is <don't let it go into automatic stop>, but I don't think that is a rightful solution.

I hope Apple will look into it, otherwise we will have to return ours mac mini while its still on warranty.

I have it whenever the mac sleeps for a long time.

My workaround was to stop sleeping the mac, period.

New Mini sucks. I've had problems since day 1 (literally). They won't do a mail in replacement, and since I'm disabled and have no car, and the Apple store is 20 miles away...

That's what I was told the first time I called too, they wanted me to take a brand new, not working properly computer since day 1 computer to the mall to be fixed 45 minutes away. Then after fuming for 30 minutes I called back and got someone who actually helped me. I was able to have a second one shipped to me (had to pay for it) and sent the original one back for credit. Unfortunately the second one was the same as the first so that one ended up going back as well. I don't have time for those kinds of problems on a brand new computer. My advice... Call back and fight!