Want to highlight a helpful answer? Upvote!

Did someone help you, or did an answer or User Tip resolve your issue? Upvote by selecting the upvote arrow. Your feedback helps others! Learn more about when to upvote >

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

mfehr Author

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

Best reply

mfehr Author

Level 1

49 points

Posted on Oct 14, 2017 1:17 AM

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.

View in context

42 replies

Franck S

Level 1

4 points

Nov 29, 2017 10:43 AM in response to Shirkan79

I think that my issue is worse because I can't even get an image either in the startup manager or from macOS Sierra installer (bootable key).

petralyn

Level 1

4 points

Nov 29, 2017 10:54 AM in response to Shirkan79

I don’t have space on hdd for rollback. And NO Apple support.

Sent from my iPhone

Petra Lynn Hofmann

331.642.0625

Dec 6, 2017 3:03 PM in response to krupal

Hi. Unfortunately, I tried to reboot from the Internet Recovery (command+option+R) but it didn't unlock the HDMI output.

Willso7

Level 1

4 points

Dec 10, 2017 7:17 AM in response to mfehr

Same problem here, i have to unplug and replug the HDMI .......... Hope Apple fix it soon.

Willso7

Level 1

4 points

Dec 10, 2017 11:37 AM in response to Franck S

Hi Frank, yep i have an image when i replug it. So for now i do not let the mini to go on sleep mode.

Dec 12, 2017 8:32 PM in response to bastugatan

Today I created a new user account, logged in there and then back to my old. Then my screen issues were gone. So simple.

Dec 12, 2017 9:12 PM in response to bastugatan

I thought ... Now the problems are back again. When I wake up my Mac mini, the screen is black. Must press the power switch to make the screen respond.

brogon

Level 1

4 points

Dec 19, 2017 8:23 AM in response to mfehr

I have a workaround that runs the cscreen utility twice with two different resolutions at login. I'm having a difficult time posting the details here. I'll try later.