Mac mini M4 screen go black randomly

I have been having issues with my Mini M2 blacks out, no sound or no video output for a short second, sometimes when it comes back, there is no audio, from the Mini for an extended time, it is very frustrating and seems like it's getting more frequent, I captured a video of it happening twice within 3 minutes.

I have tried USB-C to HDMI and HDMI to HDMI. There are no issues with the monitor; I have no blackouts when using my Xbox on it.

https://youtube.com/shorts/SrQ1wnG5Gew?feature=share

Since swapping, I've noticed a significant decrease in the blackout. Maybe only once or twice over the past three weeks or so. Like @richsadams it's still the main/left monitor, but much less blackout in this configuration. Still, should be a better experience.

I know I'm gonna jinx myself, but I tried my MSI 4K 32" monitor again, with USBC > DisplayPort cable and after 3 days I have not had a single blackout. Still on Sequoia 15.5. It is running at 144Hz/4K. Be nice if this continued, love the bigger monitor.

Not sure why, but I have had no blackouts at all on my problematic MSI 4K 32" gaming monitor. I am currently using a USBC > DisplayPort cable and it hasn't done it once in 10 days now. Previously it would do it multiple times a day, sometimes within a few minutes of each other. The Mini defaulted to 144Hz too, and I'm afraid to touch it - no reason to since that's the max refresh of the monitor anyway.

I am using the USBC connector closest to the HDMI out on the M4 Mini, not sure I used this specific port before. But at the moment mine is working correctly and has been for a week and a half now. So strange.

ChupacabraZZZ wrote:

Not sure why, but I have had no blackouts at all on my problematic MSI 4K 32" gaming monitor. I am currently using a USBC > DisplayPort cable and it hasn't done it once in 10 days now.

What changed between you having blackouts and now; the cable, port or both?

Previously it would do it multiple times a day, sometimes within a few minutes of each other. The Mini defaulted to 144Hz too, and I'm afraid to touch it - no reason to since that's the max refresh of the monitor anyway.

I am using the USBC connector closest to the HDMI out on the M4 Mini, not sure I used this specific port before. But at the moment mine is working correctly and has been for a week and a half now. So strange.

Thanks for the feed back.

I tried booting mine in safe mode back when it was acting up, and my MSI monitor blacked out then too, so I don't think it's a software issue.

Knock on wood, I'm going on almost a month now without a single blackout using a back-panel USBC port to a DisplayPort adapter cable. I know I tried this before and was still having blackouts. Only difference is that I ** using the USBC port closest to the HDMI port. Doubt it makes any difference, but it's been 100% solid since I swapped the problematic MSI monitor back in with this configuration.

If I use the HDMI port on the M4, it will black out frequently with my MSI 4K monitor, and very, very rarely on my older Dell 4K monitor.

I ** still of the opinion that it's a hardware defect primarily with the HDMI port but that's just a SWAG.

OK, so now why is this forum replacing the word "a m" (no spaces) with ** in my post? Why?

Just an update - as I've reported this several times generally as they occurred - lately it's *rare* that it happens now whereas it seemed to occur a few times a week previously, but last month and just now, i've had an occurrence (I can literally count to ~4 when it happens) of a blackout. The blackout times are consistent (3-4 seconds) every time it occurs. As far as video - it's simply a complete blackout of the screen which then returns. I simply wait and count and it's back.

Again my setup is USB-C to USB-C high speed cable (i've tried different USB-C cables) to a single ASUS PC27JCV display. It doesn't seem to matter what port, and this time occurred soon after waking from sleep and I had no visible disk activity with my attached external drives (which I thought were involved in previous iterations of instances).

I should add i'm current on versions, etc: Sequoia 15.5 (24F74).

Okay, it's back again. This time the right screen is going black momentarily, but I'm sure that's due to how I arranged the screens as noted earlier. Basically it's still the primary, number one screen that's doing it, it's just that I have it configured as the secondary screen.

Lasted a little while, but it's doing it again.

So after all of the equipment changes and configurations, this has to be a hardware issue with the M4 Mac Mini.

Per @Old Toad I've reported it to Apple. Hopefully they can resolve it sooner than later. It's not the end of the world but it is very annoying.

Suggest anyone that's having the same issue report it as well:

Feedback - Mac mini - Apple

I get the same blacking out for 1-2 seconds with my Mac Mini M4 w/32" LG 4k monitor. It happens maybe once a day. Maybe more when I'm not at the computer as I don't sleep the Mini, just use the screen saver.

It doesn't affect the usability of the Mini, just sneaks up on you.

It can't be power cord related as that would shut down the Mini entirely. The HDMI cable is new, came with the monitor. Checked both ends of it for a firm connection.

It can't be software related as it's happening with earlier Minis that run earlier systems. That leaves a hardware issue of some kind.

I’m not sure if this is a cure for the momentary screen blackouts we’ve all encountered, but since I made one change, it hasn’t happened again for about a week. Here’s what I did with my LG dual-screen setup - the left monitor connected via C/Thunderbolt and the right monitor connected via HDMI:

1. Disconnected and swapped the cables that were connected to the monitors (leaving them connected in the same positions on the M4 Mac Mini) while everything was on. This changed the right monitor to the main/#1 of course.

2. In System Settings > Displays I swapped the right monitor to the left side by clicking on the right monitor image and dragging it to the left - rather than using the “Arrange” option.

Per my previous posts, I tried swapping the physical monitors, swapping the cables, replacing the cables, etc. and the left monitor would still briefly go black (never the right).

Again, it’s been about a week, so I cannot be sure it won’t happen again at some point, but so far this seems to have resolved it for my particular setup. Not sure what I’d try for a single monitor other than what folks have already suggested.

It’s above my pay grade, but maybe one of the experts here can make a guess as to why what I did, or for that matter what @ChupacabraZZZ did, that would resolve the issue. It’s clearly a hardware problem IMHO, but there may be a solution?

[Edited by Moderator]

HDMI should always be the last choice for a computer connection. Does the monitor support DisplayPort? If it does, use that.

I have the same issue on an Asus 4K display with HDMI using 2560 x 1440. After trying all kinds of things , yesterday I changed from 60HZ to 50HZ and so far, so good.

Reseat the connections of cable on the mini and the monitor. If that doesn't help, try a different cable.

Also check the power cord to the monitor. I had that happen where it was just loose enough that the monitor would blank out every so often, then come back.

As I understand it then, the monitor cable is permanently attached, and has been repaired on top of that?

If so, that sounds like the case of a bad cable. It worked fine on the other mini - as long as no one touched it. But being moved and flexed to connect to the next mini has caused a bad connection that was already there to show itself.

Short of replacing the monitor, about all you can do is jiggle the cable so the mini can get a signal.

It does depend on the quality of the monitor, but HDMI is, first and foremost, a TV connection. And by quality, I mean cheaper monitors often limit HDMI to the original HD resolution of 1920x1080, regardless of any higher resolutions the monitor can support under a DisplayPort or USB-C Thunderbolt connection.

That, and over the years, I've seen far too many posts here by folks trying to use HDMI. Issues which disappeared when they used their monitor's DisplayPort option.

I have an EIZO monitor that allows me to use DisplayPort, USB-C or HDMI. Given the cost of these monitors, I know HDMI would work (with a proper high speed HDMI cable), but I'm still going to use a connection meant for computer monitors before I'd even consider HDMI.

Having an HDMI port is intended for video work. It eliminates the need for a break-out box. You use DisplayPort or USB-C to a monitor for your work screen in Final Cut Pro, Avid, Premiere Pro, DaVinci Resolve, etc., and a separate HDMI output to a reference monitor (TV) to see how color will appear on a TV as you simultaneously work in your video editor.