FIXED (workaround): Mac Mini HDMI not working - now working

[B74A]

HDMI from Mac Mini to a TV or monitor not working? I had that problem too.

-

Fairly new Mac Mini, and our only display is a 2019 Samsung 50" TV.

The TV says "No Signal" whether using a HDMI cable from the HDMI port, or the USB-3 to HDMI cable. Tried various combinations of ports and cables.

I found one way to make it work:

1. Make sure Mac Mini is switched off
2. Turn the TV on, and select another HDMI port than the one used by the Mac Mini (whether there's a signal or not, doesn't matter)
3. Click the Source button on the TV remote control, and arrow to the side to highlight the HDMI port number where the Mac Mini is connected to, but do not select it until ...
4. Click the "enter" button on the remote, to select that HDMI port number, while simultaneously switching the Mac Mini on.

When doing this, all is fine - the picture comes on as it should (after a few seconds).

Anything else I do, any combination of cable I try, doesn't work. But this seems to consistently work.

My guess is that the Mac Mini is looking for an HDMI when it's starting, as the TV is looking for an HDMI source when you select that input. They apparently only do that for a few seconds (maybe 10 seconds?), and if they don't do it at the same time - no picture. The TV will say "no signal" and give up. The Mac Mini will say "No HDMI connected", and also give up. Unless they look for each other at the same time.

Not ideal, but at least I have found a consistent way to make it work.

Anyone else with HDMI problems on a Mac Mini, please try this procedure and see if it works. If it works to fix this, Apple and/or Samsung should be able to "meet somewhere in the middle" and make a permanent fix for this problem. One more guess: They will both blame the other party for not conforming to whatever standards rule HDMI ...

 

[iambarney]

Hi, thanks so much for posting this!

I've had my Mac mini for well over 2 years and have never, ever had an issue with HDMI. I did, however, recently get a new Dell monitor (SF2721DGF) but the Mac mini was playing very nicely with it for over a month now.
I regularly switch between my work laptop and my Mac mini throughout the course of the day (sometimes dozens of times a day) with zero issue .. until today.
I'd switch over to the HDMI 2 input and .. nothing. Unplugged the cable, tried a new cable, rebooted, reset PRAM/NVRAM to no avail.

Then I stumbled across this post! For whatever reason, your workaround solution works and I created an account just to say thank you for posting the solution. I'm replying to this post to hopefully give another random user confidence that this will fix the issue.

 

[B74A]

Hi, thanks so much for posting this!

I've had my Mac mini for well over 2 years and have never, ever had an issue with HDMI. I did, however, recently get a new Dell monitor (SF2721DGF) but the Mac mini was playing very nicely with it for over a month now.
I regularly switch between my work laptop and my Mac mini throughout the course of the day (sometimes dozens of times a day) with zero issue .. until today.
I'd switch over to the HDMI 2 input and .. nothing. Unplugged the cable, tried a new cable, rebooted, reset PRAM/NVRAM to no avail.

Then I stumbled across this post! For whatever reason, your workaround solution works and I created an account just to say thank you for posting the solution. I'm replying to this post to hopefully give another random user confidence that this will fix the issue.

Hi iambarney,

I often look for solutions online, when something doesn't work the way I want. We all benefit from problems solved by others, and I am happy that in this case, I could be of some help. There IS another thread, about this similar issue, but I thought it was so important what I found that I "had to" make a new thread with just that (including my solution). Often, when someone has an issue, the first many posts do NO provide a solution. In this thread, the solution is in post #1 - easy!

I am, however, also interested if there are users out there who has this problem and it is NOT fixed by this workaround. And ideally, Apple AND Samsung must find a fix for this. At least there should be some kind of option to "rescan" the ports, AND keep it for more than just a few seconds. Like a minute? So you don't have to juggle with pushing two buttons at the same time.

I would say, the Mac Mini is the one that's most critical here. It's easy to switch back and forth between HDMI ports, or even switch a TV on and off. But to have to switch the Mac Mini entirely off (without being able to see the screen to shut it down ...), that is not only time consuming but also often forces you to hold the power button (or remove the power supply cord) for a forced power off of the Mac Mini.

 

[B74A]

Some say that instead of rebooting, it is enough to simply unplug the HDMI cable then plug it in again. That didn't work for our setup, but maybe it does for yours?

More reading here:

HDMI to external monitor not working unless plug/unplug on Mac Mini 2020

I am connecting a brand new Mac Mini (2020) via its HDMI (2.0) connector with a HDMI to DVI cable to an 1080p external monitor on Catalina 10.15.4. The display shows a black screen and the only way to see the image is to disconnect the cable from either end (HDMI or the DVI) and connect it...

forums.macrumors.com

Mac Mini 2018 HDMI failes after OS upgrade / patch

This is #macmini2018hdmigate ... Mac Mini 2018 -> no HDMI after OS Upgrade is a known problem. Apple support confirmed to me today that they know that and are working on a solution. The problem started with Mojave 10.14.6. The only permanent solution today is to go back and stay on Mojave...

forums.macrumors.com

In many cases, it was a problem that occurred when upgrading from Mojave to Catalina. Some reverted, and it worked again. Maybe the latest Catalina upgrade a few days ago fixed this? I am not close to my own Mac Mini so cannot check it.

 

[harriska2]

Weird. I have a 40" Samsung and use HDMI with my 2018 mini. Never had a problem and am still running Mohave. I'm worried Big Sur will mess up HDMI on my mini - love the sound that comes out of my monitor so I don't want to use an adapter to thunderbolt or whatever else.

 

[james_sa]

I've been using PRAM reset every day since I bought mini + 4k display to make it work. You method works perfectly. Now I am doubting the same thing, display boots up to slow that Mac mini failed to handshake or something. Your answer should be included in Apple Support website.

 

[lookitupkid]

Holy ****, that WORKED!!!!!! Thank you so much!!!!

HDMI from Mac Mini to a TV or monitor not working? I had that problem too.

-

Fairly new Mac Mini, and our only display is a 2019 Samsung 50" TV.

The TV says "No Signal" whether using a HDMI cable from the HDMI port, or the USB-3 to HDMI cable. Tried various combinations of ports and cables.

I found one way to make it work:

1. Make sure Mac Mini is switched off
2. Turn the TV on, and select another HDMI port than the one used by the Mac Mini (whether there's a signal or not, doesn't matter)
3. Click the Source button on the TV remote control, and arrow to the side to highlight the HDMI port number where the Mac Mini is connected to, but do not select it until ...
4. Click the "enter" button on the remote, to select that HDMI port number, while simultaneously switching the Mac Mini on.

When doing this, all is fine - the picture comes on as it should (after a few seconds).

Anything else I do, any combination of cable I try, doesn't work. But this seems to consistently work.

My guess is that the Mac Mini is looking for an HDMI when it's starting, as the TV is looking for an HDMI source when you select that input. They apparently only do that for a few seconds (maybe 10 seconds?), and if they don't do it at the same time - no picture. The TV will say "no signal" and give up. The Mac Mini will say "No HDMI connected", and also give up. Unless they look for each other at the same time.

Not ideal, but at least I have found a consistent way to make it work.

Anyone else with HDMI problems on a Mac Mini, please try this procedure and see if it works. If it works to fix this, Apple and/or Samsung should be able to "meet somewhere in the middle" and make a permanent fix for this problem. One more guess: They will both blame the other party for not conforming to whatever standards rule HDMI ...

 

[ageorgios]

I have the same problems, although a shutdown of the mac mini and a start does the job with a Samsung TV 4K 2015 that I have. I wonder why this happens and why this is not fixed yet...

I suspect the Anynet+ (CEC) to be somewhat buggy.

 

[lookitupkid]

Well crap....I celebrated too soon. It DID work initially, but now that method is not working at all, despite several attempts. I had used my projector several times in the past few days, but today the HDMI connection was lost, and I can't get it reconnected. Works just fine hooked to my iPad, but my Mac Mini has no clue that there's an HDMI cable connected to a projector. $200 cable..... ??‍♂️


Update: I tried the following, and it worked. I guess we'll see if it continues to work right. ??‍♂️

From: https://developer.apple.com/forums/thread/651131

After I did that, I followed the previous fix posted by the OP, and everything mirrored properly. I restarted my Mac Mini a couple times, and after each reboot, it was still mirroring on my projector.


ANOTHER Update 12/15: The above worked for the past 3 days until I discovered that my computer had restarted on it's own and the login screen was a rainbow color instead of my custom screen. I logged in, and while everything else seemed okay, I'm back to square one and can't get the Mac Mini to recognize that the HDMI cord is even there. NONE of the above will work. I'll call Apple Support at 6AM

 

[dalibor1984]

Try to turn off AutoSwitch-Input (or option with similar name) on your TV or monitor. This resolved my issue with Mac mini HDMI output. I connected PC and Mac mini on the same monitor and couldn't see any output from Mac, until I turned off this AutoSwitch-Input option on my monitor. Now I manually select input I need, PC or Mac.

 

[harriska2]

Try to turn off AutoSwitch-Input (or option with similar name) on your TV or monitor. This resolved my issue with Mac mini HDMI output. I connected PC and Mac mini on the same monitor and couldn't see any output from Mac, until I turned off this AutoSwitch-Input option on my monitor. Now I manually select input I need, PC or Mac.

Interesting. My Samsung 4k is on a manual switcher. I use the remote control to switch the source. Never a problem.

 

[MJones524]

Just started having this problem with my Mac Mini. I have 2 monitors hooked up, one right to the HDMI port, one to a thunderbolt-to-HDMI adapter. The monitor connected to the adapter works fine. The monitor connected to the HDMI port would sporadically lose signal, or not find signal at all. I'd have to turn the monitor off then on, sometimes it would work. Yesterday it didn't work at all thru the HDMI port. I tried the other monitor, the one connected to the adapter, and connected directly thru the HDMI port. No signal. I have a Thunderbolt hub, that I was using to connect USB devices, that has an HDMI port on it. I tried the monitor thru the hub and it worked right away. So now both monitors work fine thru thunderbolt adapters.

 

[steinmb]

Just started having this problem with my Mac Mini. I have 2 monitors hooked up, one right to the HDMI port, one to a thunderbolt-to-HDMI adapter. The monitor connected to the adapter works fine. The monitor connected to the HDMI port would sporadically lose signal, or not find signal at all. I'd have to turn the monitor off then on, sometimes it would work. Yesterday it didn't work at all thru the HDMI port. I tried the other monitor, the one connected to the adapter, and connected directly thru the HDMI port. No signal. I have a Thunderbolt hub, that I was using to connect USB devices, that has an HDMI port on it. I tried the monitor thru the hub and it worked right away. So now both monitors work fine thru thunderbolt adapters.

Did you try a reset of the SMC? - Normally do the trick on my Mac mini 2018 model if the internal HDMI port is not working.

 

[mat_icardi]

same problem here with a new Mac Mini M1, HDMI port not working properly with Samsung TV. Adapter works just fine. any suggestion? @MJones524 have you tried contacting Apple?

 

[tgoecke]

same problem here with a Mac mini 2018 i7, HDMI port not working properly with LG 4k 27UL850. No signal after power on / sleep mode.
SMC, NVRAM reset did not change. after NVRAM reset monitor works once, until next power on

 

[tgoecke]

Setting displays settings from displayport 1.4 to 1.2 helped.
LG 4K not black anymore after boot

 

[brdeveloper]

I'm also having the issue with a Mac Mini 2018 and an old LG 1080p TV. My Mac Mini 2012 didn't suffer from this issue, that is, after a sleep, display become black and only recovers after switching inputs in the remote control for a while.

 

[tgoecke]

I'm also having the issue with a Mac Mini 2018 and an old LG 1080p TV. My Mac Mini 2012 didn't suffer from this issue, that is, after a sleep, display become black and only recovers after switching inputs in the remote control for a while.

Confirmed, switching inputs back and forth helps. But not a solution for ever....

 

[ageorgios]

I have the same problems, although a shutdown of the mac mini and a start does the job with a Samsung TV 4K 2015 that I have. I wonder why this happens and why this is not fixed yet...

I suspect the Anynet+ (CEC) to be somewhat buggy.

Same here with Samsung TV 4K 2015, not found a solution other than complete shutdown and restart.

 

[yellowhelicopter]

It may be a hardware problem (in SoC itself or video output circuit).

 

[steinmb]

I see people reporting that MacOS 11.3 Beta fix their HDMI port problem. Can anyone in here confirm that?

 

[Flexblink]

MacOS on Mac mini 2018 doesn't appear to be compatible with LG Smart TV's 'Auto Device Detection'

Settings > Network > HDMI Device Settings > Auto Device Detection

I turned this setting off and the TV works wonderfully as a monitor.

 

[brdeveloper]

Confirmed, switching inputs back and forth helps. But not a solution for ever....

One thing that worked to me: using an original Apple bluetooth keyboard wakes up the Mac Mini 2018 properly. Not an ultimate solution, though, since I prefer using my Logitec wireless keyboard.

 

[besht2003]

I wouldn't update based on reports on beta success. I have Mac Mini 2018 and have uploaded all betas released and my HDMI port remains inoperable. I haven't tried turning off the Mac Mini and then turning on the TV and then changing the designated TV port at the same minute I turn the Mac on. I have tried turning off the Mac and then turning on with the HDMI connected from the TV w/out synchronous set your watch go timing and without success.

 

[besht2003]

As far as the Mac Mini 2021 M1 it is only rated to support two displays--and as there are only 2 thunderbolt ports (down from four in the Mac Mini 2018 or the Mac Mini 2021 Intels) you are at a disadvantage if the HDMI is not working. That HDMI may be needed for the second display if the M1 (like the Intels) can only support one display for one T3 controller (for two T3 ports). With the Intels you may not be able to get the rated 3 displays if the HDMI doesn't work but with adapters (USB-C to HDMI) you can manage two.