Display Won't Respond After Sleep

[RyanC1384]

I need the help of the forum badly. I received my Mac mini and have it connected it to my LG 38UC99 UltraWide monitor via HDMI. I'm running into a serious problem though.

Every time the computer sleeps and turns off to the point where I have to hit the power button to boot, the monitor won't show the screen. It just says "no signal". I've tried to unplug and plug back in the connectors but that doesn't fix the issue. It does this with both the USB-C connection and HDMI.

The sound works because I can hit Command F5 on my keyboard and hear that I'm in the login screen. When I hold down power and reboot the Mac mini it sends me to the reset password screen every time.

This is obviously unsustainable. I'd like to just walk away for as long as I want, come back in my office and move my mouse and be at the login screen right away. Hitting the power button would okay - but not if every single time the "no signal" comes up and I have to do the workaround with my keyboard.

Any ideas on how I can solve this issue?

 

[Alexandberg]

Experienced the same thing yesterday on my 2018 i7/8/128, after been using it flawlessly for two weeks.

Also, yesterday night I decided to turn it off instead, instead of just putting it to sleep. I just turned it on again, and now it won't recognize the display, connected via USB-C. The Mini is on, as VoiceOver works, but there's no display. My monitor is not however display the "No signal"–message, but just goes to sleep like the Mini is not on.

Edit: The Mini went to sleep by itself after a while, which prompted the "No signal"–message on the monitor. I turned the Mini on again, and this time it worked fine. Won't tolerate this happening on a regular basis though...

 

[ncrypt]

Also see these threads about this issue:

https://forums.macrumors.com/thread...rtup-when-using-usb-c-to-displayport.2157964/

https://forums.macrumors.com/threads/2018-mac-mini-blank-screen-on-wake-from-sleep.2156262/

 

[djc6]

Interesting. I setup my mac mini 2018 on Nov 20th and have had no issues waking from sleep until this weekend. Yesterday I had to hold down my power button twice to restart - reconnecting power cables & reconnecting display cables didn't help.

I was running 10.14.1 the first time - performed update hoping that would help (it didn't). So I was running 10.14.2 the second occurrence yesterday.

I have two LG 27UD58P-B monitors - one hooked up via HDMI 2.0 cable, another via USB-C to HDMI 2.0 active cable.

 

[dimaspivak]

Get in touch with Apple Support. They'll have you run a utility to collect logging information and ask you to pass along when the incident happens (down to the second), which will hopefully give them enough information to address this problem that a bunch of us are having.