Mac Mini (2018) Serious Monitor Issue

As I’ve written already, you need to forget about connecting HDMI/DisplayPort devices directly to the Thunderbolt port. You may get it to work partially but run into problems with waking from sleep/blanking etc. To me it seems this is by design, no issue with your Mini. You could wait for an update but don’t count on it.

The only way to make your setup work flawlessly is to connect to HDMI, and to TB, only those devices that are Thunderbolt 3 certified i.e. the dock. Changing the receiver is optional but it makes it future-proof. The projector doesn’t have to be 4K. But you absolutely need to replace the converters with a proper graphics-card equipped dock like the one I’ve shown.

I understood your point.

however, you can see that something is not right in sound and preference system on the mac.

doing a fresh install doesnt help or change anything..

you are saying to forget the usbc hdmi adapter.

Ok but it’s working great when i am plugging only one display to the mac.

It still working great when i am pluggin two external display on the mac, the display connected with usbc hdmi has no problem. However, it seems to create a conflict with the other one connected, either on hdmi direct, either with usbc hdmi.

I am listening to you when you say i need to invest. But clearly, the problem doesnt look it’s coming from adapter. The problem looks like the mac cannot hande multiple external display, depending of the configuration.

That’s correct, and I speculate that it’s by design that way. There are also known incompatibility issues with HDMI over DP 1.2, specifically the non-support for HDMI CEC commands that adapters cannot solve. DP 1.3 is expected to solve them, however Apple TB3 is limited to native DP 1.2 only.

Your observations don’t mean anything other than confirming that using TB3 to directly connect HDMI is problematic. Go the dock route, should work.

I have a monitor problem as well.

When I try to wake up my Mac mini 2018, the Dell U2410 ( HDMI connection) gets stuck in a cycle of turning on / black screen / into standby ... repeat

The only way out is to power down the monitor and start it up again.

The Dell 2407WFPHC has flicker problems ( using Thunderbolt 3 to DVI STARTech.com converter ) the screen will corrupt as if the signal has gone.

This the the second converter I have tried and had the same result from 2 different makes.

This is not what I was hoping for in a new and expensive Mac.

Hi

here is the link https://www.amazon.co.uk/StarTech-com-USB-DVI-Adapter-Thunderbolt-White/dp/B01BJ0JCBC/ref=sr_1_1?s=electronics&ie=UTF8&qid=1546432092&sr=1-1&keywords=STARTECH.COM+CDp2Dviw+USB-C+to+Dvi+Adapter+-+White

My 2 monitors have been used for many years I have connected to all the inputs with and with out converters for may different devices (PC/Apple TV/Mac Pro/CCTV/Camcorders/DVD recorders) never had any problem until this Mac mini. I think there is something amis with the video output of the Mac mini. But what do I know I just give apple lots of money for stuff that mostly works !!!!

It’s marketed as a USB-C converter, not Thunderbolt 3. They are not the same even though the connectors are identical. So ditch this converter and ANY converter that does not have the Thunderbolt logo on it. Does the HDMI work well standalone?

ahhhhhhhhhh tanks a lot.

I was talking about that since three weeks.

That's insane to me. I paid more that 2k for that.

It's crazy that the mac mini cannot handle mutliple screen (maybe not always, but sometimes depending of the screen).

only one screen works perfectly on the new mac mini 2018.

problem happen when you use two external display, whatever the adapter or any cables.

something is wrong with the handling of certains external displays (not all displays), but the problem happen only when two external displays are plugged. (even if you use one display only)

not exactly.

One is connected hdmi direct.

The other one usb c to hdmi (apple adapter, belkin, i tried maybe 4).

Whatever which display is connected with what, it doesnt matter.

One of the screen always lose signal sometimes (randomly). It's always the same display, the projector through my receiver.

The crazyest thing is that is working perfectly well in stand alone (only one screeen plugged).

USB C whether by Apple or Belkin is not the correct cable/adapter to plug into the Mini Thunderbolt port at least not for monitors. You need something that is Thunderbolt 3 and is marked by the TB logo. None of your cables/adapters do.

They are both USB C, not Thunderbolt, therefore unsuited for Display connections/adapters.

Look for a Thunderbolt 3 dock which supports your displays like the one I have quoted in an earlier post. There are probably others for DVI DP etc. The important thing is that they are Thunderbolt 3 certified.

There are no Thunderbolt 3 certified to DVI adaptors that I can find. I got one from amazon that said it was but I had the same fault with the display. I then got the StarTec one (see link in last post) which is USB-c and that works better but still not flicker free. When the equipment (Mac/Dell 2407) gets wormed up the problem stops ! Apple do say that USB-C is compatible with Thunderbolt 3 port but of cause only works as USB-C.

I had the same impression but not sure.

My external display looks better after warm up.

Most part of the time, i am losing signal during the first 2 hours. How come?

For me TB3 and USC-C are the same. That's what Apple said.

But i will order like Hcitas suggested a dock TB3 certified to check.

I will let you know.

Whatever, all these monitors issues are Apple fault 100% and it's crazy.

The mac is expensive and old mac never had these kind of issues.

Nothing is wrong, your issues are unique to dual monitor setups. Your dual monitor setup i.e. HDMI plus HDMI/DVI over TB3 with 3rd party adapters is not stated as supported, therefore you need to move to a dock where the TB3-certified dock provides dedicated connects. Just do it.

My issues are not unique...sorry.

Mac Mini 2018 had theorically handling 4 to 5 external display in the same time in 4k!!!!

That's not me sayting that, but apple!

Moreover, i am using Apple Adapter, not 3rd party.

I ll try what you said, and will see.