Mac Mini (2018) Serious Monitor Issue

Hello,

i didn't think about that. Might solved the issue but looks crazy too me.

The new mac mini must manage 4 screens in the same time theorically. It's insane to use a HDMI switch.

Before doing that, i have an idea.

The adaptater that i am using is this one:

https://www.apple.com/fr/shop/product/MJ1K2ZM/A/adaptateur-multiport-av-num%C3%A9rique-usb%E2%80%91c

Maybe it's the one creating intermittent black display to the other screen connected by classic hdmi direct.

I will try this one:

https://www.apple.com/fr/shop/product/HKQ22ZM/A/belkin-usb-c-to-hdmi-adapter

Then, if not working, these on amazon:

https://www.amazon.fr/CHOETECH-Adaptateur-R%C3%A9solution-Thunderbolt-Compatible/dp/B01N6DCH1K/ref=sr_1_5?ie=UTF8&qid=1545901170&sr=8-5&keywords=usb+c+hdmi

This one for my classic fulld HD Tv Sony

https://www.amazon.fr/CHOETECH-Compatible-Thunderbolt-MacBookPro-ChromeBook/dp/B01M02FLYO/ref=sr_1_7?ie=UTF8&qid=1545901170&sr=8-7&keywords=usb+c+hdmi

This one for my receiver Yamaha connected to my projector Epson.

I feel that something is creating intermittence and it happened only when 2 screens are plugged, even if i am using one screen at the time.

The intermittence happen always on the projector.

As i said before, it never happened on MacBook Pro 2011 or 2017, with same materials around.

If you have an idea, please let me know.

Thank you for the response to try the LG app to update the firmware. I've tried this app (https://itunes.apple.com/us/app/lg-screen-manager-lg-monitor/id1142051783?mt=12), however, it displays a warning that it is not compatible with my monitor. I've also searched their website for a FW update and haven't found anything (https://www.lg.com/us/support-product/lg-27UK850-W#manuals). I think my next step will be to contact LG for advice.

Earlier this week I spent about an hour in an Apple store. Long story short, they weren't able to fix my issue, but they did have a different model LG 4k display in the store that they connected to my mac over USB-C and we could not reproduce any of the issues so they said it was a problem with my monitor or this model LG display and that I should contact LG.

so apple is wrong to sell their products:

https://www.apple.com/fr/shop/product/MJ1K2ZM/A/adaptateur-multiport-av-num%C3%A9rique-usb%E2%80%91c?afid=p238%7Cs4VqawkmI-dc_mtid_187079nc38483_pcrid_102671600198_&cid=aos-fr-kwgo-pla-btb--slid-----product-MJ1K2ZM/A-FR

https://www.apple.com/fr/shop/product/HKQ22ZM/A/belkin-usb-c-to-hdmi-adapter?afid=p238%7Cs4VqawkmI-dc_mtid_187079nc38483_pcrid_102671600198_&cid=aos-fr-kwgo-pla-btb--slid-----product-HKQ22ZM/A-FR

please let me know which one i need to buy, i ll do it.

but it's really strange because the problem is not coming from the display connected to usbc hdmi adapter. the problem happens whatever the adapter or cable, it just happen when 2 external display are plugged.

Please let me know.

I tried and bought one...

it doesnt change anything.

being honnest with you, i thought it would work.

the only way to avoid losing signal is using only one screen, even with splitter a/b, it’s not working. Crazy but true.

i tried everything.

now 2 solutions:

• mojave new release will fix the issue
• hardware problem With graphic car or logic board or something else

whatever it is, to me thats insane.

what do you think?

It says splitter in the second bullet point but I agree you should try and make it work.

I’m thinking the problem is with your Yamaha. Try a manual switch i.e. without this A/B box or the Yamaha:

1. Connect the projector direct to the Mac and see if it works
2. Remove the cable and connect the Bravia direct to your Mac. It should also work
3. Now connect both devices to your A/B and connect the A/B to the Mac
4. Assuming everything works (it really should), start troubleshooting the Yamaha.

Yamaha receiver is RX-V467.

i ordered a switch A/B like suggested. I was sure it would solve my issue but it didnt. I am still losing signal with the projector(through the receiver).

i had in my flat a splitter (not switch), i tried to see... i am not losing signal on both screen, projector or tv. As you said, it’s not What i want. But it’s good to see it’s working.

Therefore (its complicated lol)

i am not losing signal with the receiver when:

• he is plugged alone to the mac mini (without the tv), whatever the way its plugged, hdmi direct or with usbc adaptater
• using a splitter: one hdmi out to the tv, the other to the receiver

then, i am losing signal when the two external display are plugged in a normal way:

• full hd tv with usb c to hdmi adaptater apple brand
• hdmi direct cable between mac mini and receiver, the receiver taking and sending the signal to projector

(even if you reverse the connection, receiver through usbc adaptater and full hd tv with hdmi direct, still the same issue)

in conclusion, when two external display are plugged to the mac mini, the receiver is losing signal somethime for no reason!!! Or i am dumb. What would be the reason? It’s really really strange.

Ok I’m not sure I fully got it but enough to understand that you have a pro audio-video setup.

Forget about the USB-C port for HDMI. Consider one or both of the following

1. Replace the receiver with the RX-V685 which is 4K HDMI 2.1
2. Get two HDMI ports the proper way by buying a Thunderbolt 3 dock like this one

https://www.startech.com/Cards-Adapters/Laptop-docking-stations/mini-thunderbolt-3-dock~TB3DKM2HD

Together it will cost you around $800 but will give you complete freedom from splitters, adapters, dongles etc. Imho, worth it

Found this in the "Welcome to the Mac mini" that it keeps prompting you with !!!

• Connect a display to a USB-C port:Use a Thunderbolt 3 (USB-C) cable to connect the display to the USB-C port on your Mac. For older displays, use a USB-C Digital AV Multiport Adapter or a USB-C VGA Multiport Adapter to connect the display to the USB-C port on your Mac.

Nothing about it being TB3 certified !!!!

Thanks a lot.

i am not sure where you saw splitter on my link.

it’s clearly a switch. The link that you sent me is the same switch, juste the package change.

i sent a pic.

below is the link in amazon usa in english for the same product, what do you think:

https://www.amazon.com/HDMI-Switch-4K-Splitter-Bi-Directional/dp/B079JQ9XXV/ref=mp_s_a_1_3?ie=UTF8&qid=1546168091&sr=8-3&pi=AC_SX236_SY340_QL65&keywords=techole+hdmi+splitter&dpPl=1&dpID=41Si20hRD1L&ref=plSrch

Hi,

I have the Dell S2716DG display, and your issue sounds very similar to mine. When I try to wake the mac mini, it takes a good two minutes, but it eventually does wake up. It is very annoying.

I hope they fix this. Did you return your Mac Mini?

i have the same problem when booting up the MacMini (new 2018) to two Dell 28" screens via either the Display Port or HDMI connections. It doesn't seem to want to output to the two screens. I am now considering returning it and going back to my old trusted MacPro (10years old).

I have this exact issue. Very fucking annoying, especially with it being a brand new unit. I'm running it off a 34" curved alienware monitor and 4/5 times i've booted it up, I had to do the command/option/p/r routine.

Once this bastard boots i'm going to check to see if there's an updated driver that might solve this issue.

As i sais in other posts i have some trouble as well.

My mac mini 2018:

intel i7

16 gb ram

1 to ssd

mojave 10.14.2

1st problem:

I am using two external displays. One TV full hd bravia Sony from 2011 and one projector Epson Tw-1000 full hd. Both were used with old macbook pro without issue for almost 10 years.

When i am plugging only one display, either on direct hdmi or via apple adaptater usb c , i have no issues at all with display.

when i am plugging my two external display, sometimes i am losing signal with a black screen with my projector

only.

The signal is going to the Yamaha RXV467 receiver before going to the projector Epson.

I am not using both display in the same time. Either the projector, either the full hd tv.

cables are fine, i tried many.

adaptater or hdmi direct, nothing changed.

reser smc, nothing changed.

safe mode, nothing changed.

reset pram, nothing changed.

install again mojave 10.14.2, nothing changed.

format the hard drive and install clean mojave only. Nothing changed.

Most part of the time ih happend When watching videos, whaterver the software i am using.

i tried everything that apple care and apple told me to do. For me, there is a problem with hdmi management when using multiple display, depending or the display.

second problem: sometimes it’s not possible to wake up the mac after long sleep. Not with the mouse, trackpad, keyboard or rear button.

i had to power up the mac manually.

I tried to touch some features in the settingz but it didnt change anything.

nothing special Written in the console by the way for both problems.

10.14.2 didnt fix anything. 10.14.1 was the same.

Ir anybody can help or give me some news?

thanks a lot.

You’re right, there is no explicit support for multiple HDMIs on the Mac. However, you can workaround the problem by buying an manual HDMI 2-port A/B switch (cheap, check EBay). It might fix the other issue as well.

My hunch is that multiple displays are only supported when they are directly connected to the Mac without adapters. It’s probably by design on TB3. The HDMI A/B switch is matchbox size, will do the job imho. You can try the different adapters of course, however, I’m pessimistic. All the best anyways.