2018 Mac Mini - monitor problems

Yeah, I see that too sometimes. THe monitor is 160 DPI or something insane.

It's not the monitor though. I'm using a 4K TV, and if I switch to the TV output, its perfect. Switch back, it's still 160 DPI. For me, I have to reboot the mac, not the monitor, though perhaps if I just restarted the monitor the Mac would reset the connection that way, also.

Exactly the same problem here. It works fine with my dell computer monitor but not my LG43UK6090PUA.

What I'm seeing is that if you select default for this screen and then try to select Scaled (in preferences) OSX will not stay on scaled. The screen was working on scaled and then some how got switched to Default for the screen.

OSX can't seem to remember anything related to this screen. When it was working I would have to reset the scale every time.

So over it.

OSX 10.14.3

My 2008 Mac Pro running 10.11.6 AMD Radio HD 7950

HAS NO PROBLEM with this monitor. Its definitely the Mac mini and its OS

we have a mac mini 2018 connected to 2 only LG 4K monitors using USB-C to HDMI connectors. The same problem exists with us. I can force them on using Scan for Monitors and toggling it to cause a "blip" in the system but this is not optimal. Apple needs to get a fix on this problem or accept the Mac Mini back.

Every day I juggle usBC to DP plugs to the two monitors... one lg 4K and one Samsung 2560x1440. That place g and unplug process usually resets and allows the mini to see two displays. Then, I juggle all the windows onto correct screens.

it is always a guess which screen, if either, will be recognized after 12 hours of sleep. Over the past week, the 4K display gets to be the sole screen at startup... two weeks ago, it was the other screen. Go figure. Three weeks ago, the external tb3 drives would not boot.

i double checked apples web page yesterday, and they still say mini 2018 will drive two screens. I don’t believe they actually tested such configurations, as the current mini 2018 is certainly not ready for prime time reliable service in this regard

with no fix, this mini is going back to apple once the latest iMacs become available.

Can an somebody ask apple publically this morning what they are doing to fix this horrible situation?

I have 2 LG 55in TV connected via USB-C to HDMI. One screen connects with no problem but the 2nd requires restart and PRAM reset to get it pick up. We have applied the 10.14.4 update but no luck with this. This issue is not fixed. Called APPLE and they want me to contact LG, buts it not an LG problem. The computer will connect individually just not together with 2 monitors.

10.14.4 made it worse. External Acer screen no longer works. Mac mini failed to boot at all with 2 monitors, whether usbc or hdmi.

after many restarts, plug pulling, pvram resets, using a single monitor, a installation screen came up that required me to turn FileVault off. I did so, and then mini did start up. But I have zero confidence it will start tomorrow.

wasted 90 minutes this morning to boot up mini that should have taken a minute.

this is totally unacceptable.

i am calling apple tomorrow to start a refund claim. I suspect it will be a fight. This mini simply does not work as advertised.

apple quality is not good.... not reliable.... and the claim by apple that 10.14.4 fixed this is clearly wrong.

grrrrrrrrrrrrr

Tested on 10.14.1, 10.14.2, 10.14.3 and there is no difference, the problem persists. The Mac-mini starts normally with the monitor connected to the HDMI port, but when I connect the Cinema Display on the USB-C, it freezes and restarts. I found the crash logs and almost all the "previous shutdown cause" where with the code -20 and -63. I'm in contact with the Apple support and I'll post all the results here.

For the record, I _thought_ mine was fixed, but it turned out that as soon as I shut it off a second time, the problem came back. Clearly some sort of issue with firmware/PRAM (because wiping PRAM on startup fixes it temporarily).

Could be a combination. Well, it's definitely the Mini. I will say I've tried numerous cables and the USB ports, and still end up with problems with the LG. I think the LG exacerbates whatever problems the Mini itself has, partly because it has a very short and unadjustable time for sleep to kick in.

When my brand new 2018 Mac mini goes to sleep and I try to wake it, the monitor does wake but there is no monitor picture. Yes, I've done all the suggested troubleshooting. No difference. I even tried screen sharing from another Mac mini and lo, the 2018 Mac mini thinks it has an INTERNAL IN-BUILT display when there is no picture on the monitor. See attached pic below:

In reality, it has a 19" 4:3 CMV LCD external monitor attached. I'm guessing this may be part of the problem.

I add at discussion <like survival trip>, that some time to return to the <normal screen view/wake up monitor>, if you use 2 monitors, you can try to start and disable screen duplication option from system preferences > monitor panel.

That's very clever...

I think there are three basic problems going on here.

1) Unable to wake up screen — (I'm not having this issue) — helps to have another computer and screen sharing on

2) Bad/wrong cables

3) LG monitors

The first one is clearly Apple’s fault. The third one is clearly Apple’s fault. The second one, well, it's funny that these cables seem to work on any computer OTHER THAN the Mini 8,1 and one of the Macbooks.

@CG2019 touche lol. Last 2 days for me has been hit or miss whether both monitors will display or not. I'll be using the 1 monitor that manages to display and seemingly randomly the other monitor will turn on. What's also strange is my main screen will display on my 2nd monitor sometimes. I still think its software related as if it was hardware related. I would expect the 2nd monitor to never display anything.

Jez2007 - indeed, I have a setup very much like yours: 2 LG monitors both using DisplayPort -> Thunderbolt, and a Dell monitor using HDMI. My main screen is the LG, and I haven't had any problems. But the other LG (though it's working fine) always "warns" me when I wake it up that I should use the cable they provided. I'm using a DisplayPort->Thunderbolt cable I bought on Amazon. Are you using an adapter?

Th3Cr0w - they are definitely working hard to get it narrowed down. I've been talking to an engineering/QA rep every week for the past month, submitting sysdiagnose's every time I experience the issue and corresponding with the rep via email whenever it happens. They're working on it. They're going to get this stuff figured out.

As for me - I'm experiencing it with Spectre monitors (not LG, not Dell) using USB-C to DP cables purchased from Amazon.com. I have to use HDMI to recover my system whenever it happens, and usually only after multiple reboots.