Changed resolution once , now mac mini 2018 screen goes black

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Level 1

8 points

Changed resolution once , now mac mini 2018 screen goes black

I have a mac mini 2018 with a Toshiba 43UHD . The first time I turned on the mac mini it booted , then I tried to change the resolution , and the signal to the TV went off immediatly. Since then I cannot start up the mac mini. Halfway through the apple logo the signal get lost. I tried resetting PRAM , SCM , none helped. I tried the same procedure on a 50 UHD tv , with the same result. As soon as I change the resolution to anything else than the native , the mac mini can never boot properly again. How can I reset it to make it use the original display settings again? Thank you

Posted on Aug 19, 2019 1:42 PM

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Answer 1

Aug 19, 2019 11:17 PM in response to lbt79

Bummer. I had the same problem with Mojave 10.14.5 and Mac mini 2018 and LG Thunderbolt display: halfway through the apple logo the signal got lost in Recovery mode boot. LG OLED TV via HDMI had same problem but only occasionally, but sometimes a regular boot ended in black screen via HDMI.

With my setup re-inserting the Thunderbolt or HDMI cable fixed the black screen and 10.14.6 fixed the issue at least for the Thunderbolt display (I used HDMI only for troubleshooting).

https://discussions.apple.com/thread/250448992

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Answer 2

Tesserax

Level 10

151,665 points

Aug 20, 2019 9:43 AM in response to lbt79

FWIW. After seeing a number of posts here with folks having issues with their 2018 Mac minis and various (LG & others) displays, I opted to get a Dell U2718Q 4K monitor for mine. I connected a USB 2.0 cable directly from my mini to this monitor and have never had any display issues at all. That includes during startup or wake from sleep. I left the Dell's default display settings and have only changed the Resolution setting on my mini to increase the text size. It worked fine with the "Default for display" setting, but the text was a wee bit too small for my taste.

In addition, I have a Windows 10 tower (home-built gaming) PC that connects to this same monitor via DisplayPort from a EVGA graphics card using a quality DisplayPort cable. No problem with it either.

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Answer 3

lbt79 Author

Level 1

8 points

Aug 21, 2019 11:45 AM in response to Tesserax

Thanks for all who replied. The USB-C to HDMI solved the issue for me. I connected it to the one next to the hdmi port (Apple support mentioned that might be important, I don't know if that actually matters) , and now it works in 2160p . I won't try to change the resolution this time, so I cannot tel whether that works or not.

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Answer 4

den.thed

Level 10

81,754 points

Aug 20, 2019 7:23 AM in response to lbt79

I'd try another monitor, preferable a computer monitor instead of a TV.

Other options include: getting and trying a USB-C to HDMI adapter or returning it to the seller.

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Answer 5

den.thed

Level 10

81,754 points

Aug 19, 2019 4:02 PM in response to lbt79

Try a different and/or better HDMI cable.

Did you just buy the Mac Mini, is it new or used?

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Answer 6

Aug 19, 2019 9:44 PM in response to lbt79

Does re-inserting the display cable (which cable?) help? Have you updated to 10.14.6?

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Answer 7

lbt79 Author

Level 1

8 points

Aug 19, 2019 10:45 PM in response to den.thed

It is used , but still have 3 months warranty left. I tried 3 different HDMI cables, eventually I bought an HDMI 2.0 high speed one. Did not make any difference.

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