M4 Mac mini secondary display fails to wake from sleep

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Level 1

4 points

M4 Mac mini secondary display fails to wake from sleep

2024 M4 Mac mini, 16gb, Tahoe 26.3.1 (a). Often when it wakes from sleeping only my primary display wakes up (which is an Apple Studio Display). My secondary screen is an LS27D70xE (Samsung) which is where the problem presents itself.

Sometimes power cycling the Mac will help, sometimes not. Sometimes unplugging the secondary screen from the back helps, sometimes not. Currently after a power cycle I can see the secondary screen slightly glowing, but it's still blank. You can "push" another window onto it as though the computer thinks it is working ok. It's as if it is doing every thing properly except presenting a display image.

Mac mini, macOS 26.3

Posted on Mar 22, 2026 2:34 PM

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Answer 1

den.thed

Level 10

98,138 points

Mar 22, 2026 4:16 PM in response to DanMetLan

Mac's are picky, they don't like long cheap HDMI cables.

Test a short 3.3 ft 8K high speed 48Gbps or better HDMI cable.

for some examples:

https://www.amazon.com/dp/B08NX5CZTF/ref=twister_B08NPJS5DH?_encoding=UTF8&th=1

https://www.amazon.com/Avaoaa-Braided-Compatible-Support-HDCP2-3/dp/B0FZ56HH1F/ref=sr_1_1_sspa?

https://www.amazon.com/Silkland-Certified-Upgrade-Compatible-TV-6-6ft/dp/B0CQP27WZ2/ref=sr_1_2_sspa?

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Answer 2

den.thed

Level 10

98,138 points

Mar 23, 2026 1:24 PM in response to DanMetLan

Sorry to hear that.

As a test:

Turn On "Prevent automatic sleeping when display is off" in the Energy Settings.

Set "Turn display off when inactive" to 10 minutes in the Lock Screen Settings.

Then:

Leave the Mac Mini On and only allow the display(s) to turn Off

Do not manually Sleep from the Apple Drop Down menu

Shut Down the Mac when away for a day or more

Plus:

Send Feedback to Apple about this issue.

Feedback - Mac mini - Apple

Feedback - macOS - Apple

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Answer 3

den.thed

Level 10

98,138 points

Mar 22, 2026 3:02 PM in response to DanMetLan

How is the Samsung connected to the M4 Mac mini...?

(please provide complete details)

for reference:

see "Display Support" at > Mac mini (2024) - Tech Specs - Apple Support

and > Connect a display to Mac mini - Apple Support

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Answer 4

DanMetLan Author

Level 1

4 points

Mar 23, 2026 11:26 AM in response to den.thed

Well, sadly, the new Rocketfish 8K 4 foot (shortest one they had), 48gbs ultra high speed HDMI from Best Buy didn't make any difference. Same result as the cheap cable.

I believe this problem showed up with Tahoe. I seem to recall it working fine before that update.

I wish Apple had an area where known bugs are posted, so at least I could know if it was a bug that has been identified. I have seen quite a few of the same complaints though on Reddit and elsewhere.

If anyone has any other rabbit holes for me to go down though I would give it a shot. For now I guess I will just disable the screens going to sleep.

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Answer 5

Old Toad

Level 10

218,328 points

Mar 26, 2026 11:37 AM in response to DanMetLan

To add to den.thed's recommendation of not sleeping the Mini I have a M4 Mini which I've never slept the device. I put itto screen saver after 10 minute of inactivity and turn off the monitor after 1 hour. Since i'm old school I shut down at might as it's no inconvenience to boot up in the AM as all storage is SSD whether interior or exterior.

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