No hdmi signal from Mac mini

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Level 1

8 points

No hdmi signal from Mac mini

My Mac mini has no display after update, it was working fine before the install of Catalina! (I was running Mojave before the update) The screen says “no signal” when connected with both hdmi and mini display, neither work! I’ve been thru all the reset options (opt+ Command+R+P) (hold power button) etc, I even removed the hard drive and installed a different OS X but I still had the same problem when I put it back. Can’t load into safe mode, can’t load any boot options, can’t do anything but look at “no signal” on the screen. I’ve even contacted apple support with no luck.

Posted on Dec 5, 2019 10:46 PM

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Answer 1

Tesserax

Level 10

158,592 points

Dec 6, 2019 9:31 AM in response to Sammyslick

Thank you. I asked because I had a similar issue with my 2018 mini and thought the upgrade to Catalina failed. In my case, my mini is using a direct HDMI connection to my Dell 4K monitor. When I took it to my local Apple Authorized Service Provider, they connected it to a non-4K monitor and it booted up just fine to the Catalina desktop. When I brought the mini back home, I too still got the dreaded "No Signal" message on my monitor. I had a USB-C-to-HDMI adapter handy and that interestingly solved the problem. I later upgraded to 10.15.1 and was able to use the direct HDMI connection again. There is definitely something going on with Catalina that is affecting video output, and it appears, that it is not isolated to just the 2018 mini models.

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Answer 2

hcsitas

Level 6

13,970 points

Dec 6, 2019 9:04 AM in response to Sammyslick

It looks like the update failed, doesn’t look like the mini is even coming up. I would setup an appointment with the Genius Bar.

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Answer 3

hcsitas

Level 6

13,970 points

Dec 6, 2019 2:55 AM in response to Sammyslick

Details please. Monitor make/model, connected to <mini port>, cable type and length, dongles etc. Does it work with another monitor?

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Answer 4

Tesserax

Level 10

158,592 points

Dec 6, 2019 8:54 AM in response to Sammyslick

What is the model of your Mac mini?

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Answer 5

hcsitas

Level 6

13,970 points

Dec 6, 2019 12:16 PM in response to den.thed

I don’t think you understand Den. OP’s mini is not on Catalina, not on Mojave, not on no nuthin’. All signs are the machine’s bricked. Hopefully Genius Bar will recover his machine, and cheaply.

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Answer 6

den.thed

Level 10

92,530 points

Dec 6, 2019 12:51 PM in response to hcsitas

Not necessarily, the OP just needs to Startup in macOS Recovery, Erase the Drive, Install macOS Mojave, then Migrate from Time Machine.

FWIW, just because the Catalina install failed or doesn't work, doesn't mean that macOS Recovery or Starting up from another drive won't.

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Answer 7

hcsitas

Level 6

13,970 points

Dec 6, 2019 1:03 PM in response to Sammyslick

den has a point, Sammyslick. Follow instructions for recovery here

https://support.apple.com/en-us/HT201314

It *should* get you a screen with instructions. Good luck,

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Answer 8

Sammyslick Author

Level 1

8 points

Dec 6, 2019 8:28 AM in response to hcsitas

I was hooked up to a regular Vizio tv, and also hooked up to every other hdmi compatible screen in my house, it says no signal on every thing. It’s not my displays that are the problem, it’s the firmware included with the Catalina update. I need to know the way to revert my computer back to the way it was before that update because reinstalling another OS X didn’t work

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Answer 9

Sammyslick Author

Level 1

8 points

Dec 6, 2019 9:09 AM in response to Tesserax

I have a late 2012 Mac mini, I bought it off eBay. When it came, it had Mojave on it and worked perfectly. I had no problems until I was instructed to update to Catalina. The update got to the “about 5 mins left” part and the screen blacked out and said “no signal”, I thought it was restarting but it never came back on screen. I waited a smooth 15 minutes before I turned the system off then back on, but when I did it still said no signal, so I move to a different room in the house and it still said no signal

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Answer 10

Sammyslick Author

Level 1

8 points

Dec 6, 2019 10:20 AM in response to den.thed

I already tried resetting the SMC and resetting NVRAM with no luck and the cables I’m using are the same cables I was using before the update. The monitor I’m using is the same as before the update. The Catalina update is what ruined my computer. I need to know how to revert my computer back to the stage it was in before attempting to install that update.

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Answer 11

Sammyslick Author

Level 1

8 points

Dec 6, 2019 9:38 AM in response to Tesserax

Ive been reading that the usb-c to hdmi was a solution, but I don’t have usb-c. all this 2012 model has is mini display and I get the same outcome when connected to that

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Answer 12

den.thed

Level 10

92,530 points

Dec 6, 2019 12:12 PM in response to Sammyslick

see > https://blog.macsales.com/54622-how-to-downgrade-from-macos-catalina-to-mojave-or-earlier/

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Answer 13

Sammyslick Author

Level 1

8 points

Dec 6, 2019 1:01 PM in response to den.thed

I would’ve done that if I could actually see anything besides “no signal”, i can’t select any option to do any of that with no display

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Answer 14

den.thed

Level 10

92,530 points

Dec 6, 2019 10:10 AM in response to Sammyslick

Reset the SMC > How to reset the System Management Controller (SMC) on your Mac - Apple Support

Then reset the NVRAM, as per > Reset NVRAM or PRAM on your Mac - Apple Support

You may also need to try a different higher quality HDMI cable and/or the Apple recommended Mini DisplayPort to HDMI adapter with your 2012 Mac Mini. see > Belkin 4K Mini DisplayPort to HDMI Adapter - Apple

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No hdmi signal from Mac mini

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