Level 2

334 points

External display randomly turns black / goes to sleep.

Using an M2 Mac Mini. With one monitor on the HDMI port, and a second on a thunderbolt-4 to HDMI adapter.

The 2nd display is set up as "Use as separate display", so not using screen-mirroring.

At random intervals macOS will put the thunderbolt display to sleep (or turns it black).

No amount of mouse-movement or anything else will bring the display back on. To get it back on I put the whole machine to "sleep" for a moment and wake it back up. Both displays will now work again perfectly for some time.

The random amount of time can be anything from a few minutes to about 1-hour.

Mac mini (M2, 2023)

Posted on Feb 21, 2024 2:43 AM

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den.thed

Level 10

91,072 points

Posted on Feb 21, 2024 8:45 AM

Kenny Millar wrote:

@den.thed Thanks for the helpful reply.

The HDMI adapter is an ULT-WIIQ from Amazon

The monitor is a Phillips 21" can't remember the exact model at the moment.

Both work well on a PC I have - with no issues at all.

The main HDMI Output from the mac mini never has an issue either.

I will try replacing the HDMI Adapter.

I'm not finding that adapter by the ULT-WIIQ reference at Amazon.

I would test one of the following adapters listed at BestBuy.

https://www.bestbuy.com/site/insignia-usb-c-to-hdmi-adapter-black/6473497.p?

https://www.bestbuy.com/site/best-buy-essentials-usb-c-to-hdmi-adapter-white/6458562.p?

FWIW I'm using the Insignia adapter on one of my Mac mini dual display setups.

Another option, is to spring for the more expensive Apple adapter.

https://www.apple.com/shop/product/MUF82AM/A/usb-c-digital-av-multiport-adapter?

https://www.bestbuy.com/site/apple-usb-type-c-digital-av-multiport-adapter-white/5596800.p?

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30 replies

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 8:58 AM in response to hcsitas

Please explain when you say Sleep is aggravating.... since my machine IS NOT going to sleep.

Only one monitor is being put to ... 'sleep'...'standby'....'black'.....'blank' or whatever you want to call it.

As far as the energy saver is concerned the machine is 'awake' 'in use' or whatever you want to call it.

Here is the HDMI Adapter I am using.

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 9:14 AM in response to hcsitas

hcsitas wrote:

A bit too quick IMO. Snapshot to show the change? And then shut down and power up for good measure.

It happens frequently - long before any sleep timer, I already know that - you seem have trouble understanding it? But to rule out the slight chance you could be right I tried it anyway, and the screen blanked out as normal.

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 9:21 AM in response to hcsitas

hcsitas wrote:

It’s irrelevant, the PC is so…pre-2018.

LOL maybe but unfortunately some big companies (Like Lattice, Altium and Intel) still don;t make macOS versions of their design tools, and one needs to keep a PC for these things. (No I'm not interested in VM on M2 Mac Mini).

Still it porves that the HDMI Adapter can work for hours at a time without blanking out.

hcsitas

Level 6

13,964 points

Feb 21, 2024 9:24 AM in response to Kenny Millar

I have a PC too, I access it with Remote Desktop and call it the Slave. Guess who’s Master😁?

Anyway, I’m out of ideas. That said, I wouldn’t re-enable Sleep - it’s a cheeky old dog, best put down. Good luck!

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 3:52 AM in response to hcsitas

Thanks but most of those settings don't appear on an M2 Mac Mini ;-)

hcsitas

Level 6

13,964 points

Feb 21, 2024 7:57 AM in response to den.thed

As long as OP has Sleep enabled, all bets are off 😁

hcsitas

Level 6

13,964 points

Feb 21, 2024 8:25 AM in response to den.thed

“To get it back on I put the whole machine to "sleep" for a moment and wake it back up.”

hcsitas

Level 6

13,964 points

Feb 21, 2024 9:03 AM in response to Kenny Millar

You have Sleep enabled, disable it i.e. uncheck “Wake”. If it doesn’t change the problem, you are free to re-enable (I wouldn’t because it does nothing). If it fixes, no need to update here…

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 9:08 AM in response to hcsitas

hcsitas wrote:

If it fixes, no need to update here…

Or if it doesn't fix it and I just don't feel like replying.

hcsitas

Level 6

13,964 points

Feb 21, 2024 9:09 AM in response to Kenny Millar

That works too 😁👍

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 9:09 AM in response to Kenny Millar

Well guess what? It didn't fix it.

No suproises there since it's not a sleep-wake issue.

hcsitas

Level 6

13,964 points

Feb 21, 2024 9:11 AM in response to Kenny Millar

A bit too quick IMO. Snapshot to show the change? And then shut down and power up for good measure.

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 9:16 AM in response to hcsitas

BTW - keep in mind that this HDMI Adapter and Monitor setup works flawlessly on a PC I have - no issues at all.

That's why I posted about the issue here.

hcsitas

Level 6

13,964 points

Feb 21, 2024 9:18 AM in response to Kenny Millar

It’s irrelevant, the PC is so…pre-2018.

Kenny Millar Author

Level 2

334 points

Feb 21, 2024 9:27 AM in response to den.thed

Thanks.

The adapter is stright into one of the ports, the other has a USB-3 Hub on it, with charge/sync iphone cable and a webcam. that's it.

I'll try the things you suggest.

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External display randomly turns black / goes to sleep.