M1 Mac Mini, Displays wont turn on after wake from sleep

I just saw an article today on MacRumors about the most recent seeding of 11.2, which gives me hope because it included the following:

"When ‌macOS Big Sur‌ 11.2 sees a release, Apple apps will be compatible with VPN apps and will no longer be able to bypass firewalls and other security tools.

According to Apple's release notes, the update also improves Bluetooth reliability and includes multiple bug fixes.

‌macOS Big Sur‌ 11.2 improves Bluetooth reliability and fixes the following issues:

- External displays may show a black screen when connected to a Mac mini (M1, 2020) using an HDMI to DVI converter

- Edits to Apple ProRAW photos in the Photos app may not save

- iCloud Drive could turn off after disabling the ‌iCloud Drive‌ Desktop & Documents Folders option

- System Preferences may not unlock when entering your administrator password

- Globe key may not display the Emoji & Symbols pane when pressed

The update addresses a bug that could cause external displays to show a black screen when connected to an ‌M1‌ ‌Mac mini‌ using an HDMI to DVI converter, and it fixes an issue that resulted in edits to Apple ProRaw photos in the ‌Photos‌ app not to save. It also includes fixes for ‌iCloud Drive‌, System Preferences, and more.

I don't have this issue with a M1 mac mini, but i experience something very similar with my MacBook Pro (15-inch, 2017) as well with my work MacBook Pro (15-inch, 2018) occasionally.

Under some weird circumstance when waking the devices up from sleep (fingerprint or password) as well leads to my external monitors (Dell 4k at work, Eizo 4k at home) not being recognized anymore although they are still connected via USB-C (Dell) or via USB-C to Docking Station (CalDigit TS3) to DisplayPort (Eizo).

In the beginning it helped to switch the DisplayPort at the home setup monitor (Eizo) from port 1 to 2 or vice versa. This would sometimes immediately properly detect and use the external monitor, sometimes only after a restart, but this trick didn't work at the work setup (Dell) because it only has this single USB-C port.

Since i couldn't find any reports on this specific or similar issues i started to dig a little bit on my own and what worked with great reliability was to delete two specific .plist files that seem to hold your display configurations (WARNING: deleting them will reset your display settings which are configured via System Preferences > Display for all internal and external displays) and afterwards restart the MacBook.

The deletion of the .plist files can be done using the terminal.app or your preferred shell:

sudo rm /Library/Preferences/com.apple.windowserver.plist
rm ~/Library/Preferences/ByHost/com.apple.windowserver.[SOME_HOST_SPECIFIC_UUID].plist

After restarting the connected external displays are properly detected and used again. Only drawback i have (besides encountering the issue since Catalina 10.15 if not earlier) is that i have to setup my display settings (external as well as internal) again for each display.

Just deleting one of those .plist files does not work for me, i have to delete both of them before restarting in order to get the external displays running properly again.

Maybe this could be a workaround for this issue as well.

I had the same issue with an Acer ConceptD monitor and a Mac mini M1. After much researching and fiddling, I realized it had to do with the auto input selector in the monitor. I just changed it to manual input select, selected the USB C or HDMI input and it worked flawlessly. I hope this works for every other user with this problem.

A year later and it's still a problem. So much for them fixing it. Having to forego separate screen spaces in order to work around a bug in their buggy OS isn't a solution. 

The problem is the same. HDMI (main monitor) just shuts itself down after sleep and never wakes up, even un/plugging hdmi cable doesn’t wake up the display (yes, it's on). Tried lots of things, restarting numerous times. Nothing worked. BigSur doesn't even recognise that there is a monitor attached. I have to restart the computer for it to work again.

However,  "mac_i" above may have found the root of the problem as I too have a video adapter fitted into the right hand thunderbolt port and it's only been happening recently, and recently I moved the adapter from left to right usbc port.

Plugging usbc-video into the left usbc seems to have fixed it. Been a day or so and hdmi now wakes up when computer wakes up, every time (about 20 times so far). The adapter also wakes up as well (it always did).

So problems with the right hand (closest to hdmi out) seems to be the culprit.

For me, as I know the device is very low power already, I have 'solved' the issue with the following settings.

1. In Energy Control panel, enable all options (prevent,hard disks,wake,start up).
2. Set turn display off after 15 mins.
3. Enable a hot corner to turn the displays off whenever I want.

So basically, the machine is on all the time. I have not measured the TDP of idle, but I expect it is sipping anyway. Having the monitors off whenever I'm not using it is more of a concern, and this works well. I have never had the issue with these settings. I will play with it again maybe on the next release!

Installed the update, and so far, everything works perfectly. Wake from sleep has worked perfectly so far. I've tried to trip it up, but so far, so good. I DID have to go back into Sys Prefs to fix monitor arrangement after install, but everything has worked fine after that first restart so far.

I have also issues about the awaking of my monitor (I have a M1 mac mini and a Dell 32 monitor pluged with hdmi cable). But I found a way to wake it up all the time. Maybe it could give you a hint on how to solve the problem (for you and apple ingeneer!).

When it goes on sleep, the screen goes back to the login window. If I only touch the keyboard or move the mouse, it will never wake up. I first touch the keyboard (then the computer wake up) then I mouve the mouse rapidely so the cursor inflates. My hypothesis is that, somewhere, somehow, the computer need some change in the image signal. I can write a phrase in the password space, I can move my mouse slowly forever, but my screen won’t turn on. However, if I move it fast for long enough, it works. Somehow, the treshold specified somewhere is reached and the computer send the signal to the screen. So I guess that it’s a software problem (hope it is not in the controler chips - probably not if you experience the same kind of problem with usb-c output).

Nevertheless, despite my confidence in waking up my mac, it’s still pretty annoying... I’m use to barely touch the mouse for the screen to turn on...

"Anyone else with no-wake issues on an M1 Mac mini" - Thread full of people reporting issues, so that would be a yes! 😊

What you didn't mention, in your post, is the connection type you are using. In general, you will find that people using HDMI to HDMI cables, Mac to monitor, are having the least issues. Those using USB-C to DisplayPort seem to have a lot of issues. Any type of conversion cable, or adapter, seems to add to the issues.

In my case, using HDMI to HDMI with a Alienware monitor resulted in the waking problem. This was my initial setup, back in December. I very soon upgraded to an LG 4k monitor, still using HDMI to HDMI, and never had the wake issue again.

With that said, at times, my LG monitor would be slow to wake up. Nothing more than a few seconds, but long enough to make me wonder. On the plus side, this latest Big Sur update cured that problem. Now, if I move the mouse, or tough the keyboard, the monitor is quick to come to life.

If you digest the various posts here, and on Reddit, regarding the monitor wake problem, there are a few steps to try.

• Use an HDMI to HDMI cable
• Unplug any USB-A and USB-C devices that you can do without for testing
• If you have a USB-A or USB-C you can't unplug, use the port furthest away from your HDMI port

Try those and see if you have any success. Best of luck with it.

The only monitor connection that I've found works on both the 2018 Intel and the 2020 M1 Mac minis is HDMI. I've had issues with USB-C to DP, USB-C to VGA using Apple and non-Apple adapters and different brand monitors (Acer, Philips, Chimei, BENQ).

There was a long thread about the 2018 Mac mini with users mentioning they were working with support, but the monitors not waking from sleep issues were never resolved. It looks like the 2020 M1 Mac mini is going to go down the same road given Apple has been unable to resolve the issues since 2018 :(

I had the same issue with my usb c to HDMI cable to my second external monitor on my new M1 mac mini.

Simply I replaced it with a usb-c mini hub ( I bought from amazon for $19.00) with my HDMI cable plugged in this hub. all issue solved...

So after my last conversation with Apple Tech support, they notified me that this is a known problem, and they are working on it, but do not have a time frame for it. As of right now, using the Apple Multipart adapter, my problem has been reduced to the USB-C monitor just not being recognized, but turning the monitor off and on semi to fix the problem. I also bought the XSPUS 8 port adapter mentioned above and have installed it to see if it makes any difference. So far, so good, but it's only been two days.

My running workaround is to disable sleep. Sleep does not work the same was as previous models - I've had several minis over the years. As this unit has a pretty lower power draw, I'm betting it's not a huge difference, it would be interesting to find the power specs. Also - it seems to make a difference if the screens are plugged into thunderbolt docs vs usb3 adapters. There are lots of glitches like this one with the new hardware, and this is one of them. Keep posting and sharing with Apple - it's their job to fix this. Yes, we'll have to wade through the Apple apologists that keep pretending that the 'holding it wrong' argument is valid, but that's fine. Right now I've disabled sleep.

As far as “owned up to it”, I am not sure what you are looking for. Based upon my posting here, an Apple tech reached out to me about a month ago and asked for my assistance in troubleshooting a few different circumstances to help them better understand a real world example.

In my case, I had a monitor that refused to wake up 100% of the time. I purchased a new (different brand) monitor that wakes up 100% of the time. The tech sent me an internal Apple logging tool, and I walked through various combinations of different cables attached to the two different monitors.

Indisputable conclusion was that the problem was not with the Mac mini, but was with the monitor. Or, best case, the monitors driver.

So, from my perspective, Apple has been diligent in trying to figure out what the issue is. And, it does not appear to be be the mini that is the problem.

In case this helps someone else. I have mini m1 and when connect HDMI to my BenQ 3200u the monitor will not turn back on after sleeping for several hours (OS 11.2). I did find work around that works for me - I have a CalDigit TS3 plus and connected the monitor from the TS3 Plus via Display Port cable. This configuration seems to be working without the sleep problem. It appears to me that there is an issue with the Apple HDMI implementation.

I don't have an LG monitor I have a Samsung 49 "Odissey G9, I thought it was a problem with the monitor but instead it seems to be a problem with the Mac and not a small one

I never put the computer to sleep I use the screen locked and after the monitor turns off and never turns on again, the only solution is to unplug the USB C Displayport cable