No HDMI signal on Mac Mini after reboot or wake up with High Sierra

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Level 1

49 points

No HDMI signal on Mac Mini after reboot or wake up with High Sierra

I upgraded my Mac Mini 2011 from Mac OS Sierra to Mac OS High Sierra

During the upgrade process my screen went black. I was able to get it back in disconnecting and reconnecting the HDMI cable on the Mac Mini.

Every time, I wake the Mini from sleep, the screen stays black. The same also happens after a reboot. Dis- & reconnecting the HDMI cable brings it back to work. Turning my TV off and on is not sufficient.

I did a reset of the PVRAM How to reset NVRAM on your Mac - Apple Support with no change

I had to recalibrate my display as some of my e-mails were showing up in black: Re: Conversation view in Mail broken in High Sierra

Any hints?

Mac mini, macOS High Sierra (10.13)

Posted on Sep 30, 2017 7:15 PM

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Answer 1

Best reply

mfehr Author

Level 1

49 points

Oct 14, 2017 1:17 AM in response to mfehr

I found a more convenient work-around than plugging out and in the HDMI cable or connect through Screen Sharing to change the display settings back and forth to activate the HDMI signal:

I now connected a Thunderbolt to VGA-Adapter (My screen offers 3 HDMI and 1 VGA adapter) and connected the Audio connector with the screen as well. I don't like the approach as I now have additional cables to hide and VGA is rather old technology. However, the convenience to turn the Mac Mini on as I did before is more important to me.

I still hope this signal issue gets resolved with the next OS X update so I can switch back to HDMI.

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Answer 2

chris_g1

Community Specialist

Oct 1, 2017 10:53 AM in response to mfehr

Hey mfehr,

If I understand correctly, you upgraded macOS and now the connected external display is not turning on when the Mac mini wakes from sleep, rebooting, and reconnecting the display cable. It looks like you have already done some troubleshooting. I would recommend you read this article and use it to help troubleshoot the issue.

Get help with video issues on external displays connected to your Mac

Thank you for using Apple Support Communities. Have a good one.

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Answer 3

mfehr Author

Level 1

49 points

Oct 2, 2017 7:15 AM in response to chris_g1

Hi Chris,

Thanks for the links to the troubleshooting of external displays. Unfortunately, none of them solved the problem. There is additional info, I noticed worth being shared:

When I boot up, the apple logo appears as normal. The screen turns black when the autologin takes place. Actually, it is not 100% black. There is a white line of a few pixels high and about 1 cm wide in the upper left corner.
I changed the battery settings for my Mac Mini to never go in sleep mode and I left the Display sleep at 10 minutes. I noticed that the black screen is caused by the wake up from the display sleep.

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Answer 4

mfehr Author

Level 1

49 points

Oct 2, 2017 7:58 AM in response to chris_g1

I did 2 additional tests to isolate the issue:

I removed autologin to be sent to the login page first after a reboot. The screen is blank
I connect to the Mac Mini using a Screen Sharing session. When I modify the display settings to any entry, the HDMI display gets to work

So the problem must be related to the display driver and/or the calibration on High Sierra.

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Answer 5

Franck S

Level 1

4 points

Oct 22, 2017 9:12 AM in response to mfehr

Hi.

I have a Mac mini Late 2012 and after that the upgrade to High Sierra (from Sierra) was completed, I realized that the HDMI port was not functionning anymore. I used two HDMI TVs and then a mini-DP to DVI adapter + DVI to HDMI adapter to confirm this issue. I have opened a bug report (#34761100) and an investigation is actually in progress. Even the startup manager is not displayed when booting so it looks like an hardware/firmware issue. Stay tuned.

Best regards.

Franck.

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Answer 6

Nov 1, 2017 5:37 PM in response to mfehr

Mac Mini, High Sierra 10.13.1, 1TB SSD, 8GB RAM, DELL monitor.

When my Mac Mini has been sleeping for a few hours, it refuses to wake up. I am then forced to press the start button on the back to start the computer. I had the same problem with the first version of High Sierra.

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Answer 7

euskir

Level 3

724 points

Nov 7, 2017 10:33 AM in response to mfehr

Hello there,

Well, my Mac Mini (Late 2012) is having some troubles with the HDMI after macOS High Sierra, not exactly the same as you, but specially after sleep the size of the display is wrong, the dock and the finder are almost out of view, I need to unplug and replug the HDMI cable to fix the issue, more than annoying to be honest.

Any clue?

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Answer 8

Franck S

Level 1

4 points

Nov 12, 2017 12:26 AM in response to petralyn

Hi. Sorry for that. As written previously, I have a bug report (#34761100) with Apple. The issue is that the HDMI output does not work as soon as the Mac is started. So even if you boot on the Startup Manager, there is no video. So it looks like the issue is more closed to a Firmware issue than to an OS issue. I hope that Apple will find a solution. You can use your mini-DP output with a mini-DP to DVI adapter and then a DVI to HDMI adapter to plug your HDMI cable. Best regards.

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Answer 9

petralyn

Level 1

4 points

Nov 12, 2017 7:34 AM in response to Franck S

Thank You for the info. BTW,FYI. I discovered my display did indeed come up after unplugging the HDMI and plugging back in. It took roughly 5 or so min. Also, my screen saver didn’t start and the display shutdown. Again, I unplugged the HDMI, plugged in and waited. Surprise, now to keep it up until Apple gets its s... together and fixes the problem.

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Answer 10

Nov 29, 2017 10:45 AM in response to mfehr

Are there any news on this?

I have exactly the same Problem, so i got back to sierra from a TimeMachine restore...

My Mac-Mini (Late 2011) sits in the living room, connected to a LG-TV via HDMI. With HighSierra the Screen is just black with a tiny white line in the upper left corner.

Replugging the HDMI-Cable brings back the screen, until the next boot of the mini.

The mini starts up and shuts down every day on a time scedule, so i need to replug the cables after every reboot.

Thats not an option, as my TV and the Mac-Mini are build in an entertainment cabinet.

As my TV has only HDMI inputs, i cannot use any other Cable like VGA etc.

So it's impossible to upgrade to High Sierra before this Problem is fixed...

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Answer 11

krupal

Level 1

4 points

Dec 3, 2017 11:24 PM in response to mfehr

I was facing the same problem but this worked for me

1 shut down your mac mini

2 download recovery partition by pressing (command+option+R)

after recovery partition downloded just restart innormal mode.

i know this has to nothing to do with display drivers but this worked for me and if you alredy have recovery partition downloded i m sorry i dont know what to do.

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Answer 12

Franck S

Level 1

4 points

Dec 10, 2017 7:46 AM in response to Willso7

You have an image when unplug/replug. In my case, I've lost the HDMI output completely. I just tried to install Sierra 10.12.6 on an external drive, hoping that the firmware may be downgraded / updated, no fix. Then I installed High Sierra 10.13.2, also hoping that firmware may be reinstalled, no fix. Looks like the HDMI output is just bricked.

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Answer 13

petralyn

Level 1

4 points

Dec 10, 2017 11:34 AM in response to Franck S

I am SO fed up with Apple ignoring the trash the Isis video is. They have not correct the crashing in mini’s which they have posted as compatible—they are not. Further, if like me you don’t have sufficient hdd room you can’t roll back to a working version. My computer was on for 36 hour’s no crashes until I went to load a new page. Now black screen. There’s no way to know for sure the cause of the crash.

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Answer 14

Dec 19, 2017 1:23 PM in response to mfehr

I have the same issue, hope Apple will fix this soon!!

Mac mini mid 2011, macOS High Sierra (10.13.2), Intel HA Graphics 3000 512MB

My "walk-around" is:

1. Source on TV needs to be HDMI 1 = Same source as Mac is connected to.

2. Wake up Mac from sleep - The TV indicates "Incoming signal 720p" but still black screen.

3. After the TV indicated incoming signal on HDMI 1 - Switch to HDMI 2 (not connected to any source) and then back to HDMI 1. Now I can log in to my account, until next time Mac goes to sleep again, then I have to repeat.

Note: This doesn't work if I switch to TV source, I needs to be another HDMI (or maybe some other external source will also work, haven't tested all of them).

Can someone tell me how I can report this issue to Apple?

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Answer 15

petralyn

Level 1

4 points

Dec 20, 2017 6:49 AM in response to NewmanD82

I had similar issues until I found an Apple statement. This communication mentioned that Iris video does not work well, if at all, on monitors that don't support higher screen resolutions. The answer is Apple has forces the purchase of more up to date displays. As soon as I bought my new LG all worked well. And, BTW the issue with my older monitor burned out my LaCie thunderbolt 4TB hdd.

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