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Mac mini with M1 chip and Big Sur HDMI signal ceases?

Mac mini with M1 chip and Big Sur HDMI signal problem:

I have the mini hooked up to a Samsung tv/monitor via

HDMI. There are two HDMI input ports on the monitor:

HDMI and HDMI/DVI. Both will accept standard HDMI

cables. I have two minis including the one this is about.

Both generally work on either of the monitors HDMI inputs.

BUT:

Today the Big Sur mini has ceased to send and HDMI signal.

I have tried unplugging and reconnecting HDMI cables both

at the machine and at the monitor with no success.

The only thing that appears to work is to shut down the Big Sur

mini and restart it. That means I do not have screen access to

quit applications before pressing the power button to shut it

down.


This does appear to be a hardware problem. The last time the

Big Sur min was being displayed on the monitor. There was no

activity and it just quit sending the signal. The first time I was

trying to connect to the other mini over SFTP and local http

servers via local network.


As it goes I have had events where the ethernet to USB adapter

has lost connection and unplugging the USB from the machine

and reconnecting it has solved the problem. So the minis I have

seem to have some trouble keeping connections to USB, ethernet

and now HDMI.


Is this a hardware defect, a system bug, or both?


Thank you for attention

JK

Mac mini 2018 or later

Posted on Aug 3, 2021 3:40 PM

Reply
Question marked as Top-ranking reply

Posted on Aug 3, 2021 4:09 PM

That should not be happening.


Your best bet, is to contact Apple Support and have them help you with either a service appointment to evaluate the problem or an all out unit replacement. see > https://getsupport.apple.com

Similar questions

7 replies

Aug 4, 2021 2:15 PM in response to anotherJeff273

Here is an update:

Note: I have two minis with one Samsung tv/monitor

The minis are named mini15 and miniM1. The 'MBPII' referred to is a Macbook Pro on the

local ethernet network.

This query is regarding miniM1. I also had a chat session with Apple support and was

given the usual questions about cables, cable connects, reseting PRAM/NVRAM and

starting in safe mode. BUT....( notes taken as events transpired)


8/4/2021 @ 12:53 P.M. while executing update (on miniM1) the monitor lost signal and I am

not able to establish screen sharing from mini15. The power light is still on on miniM1. All the

network server listings have disappeared from mini15 finder window.


I was able to connect to screen sharing from MBPII and did have a network link to mini15.

I restarted mini15 and was able to reestablish a screen sharing connection to miniM1.

It appears to still be downloading the updates @ 1:25 P.M. That is about and hour.


Just for the **** of it I switch the HDMI channel back to MiniM1 and there is a screen.

So I can assume it was some issue with the network that was effecting mini15 (?).


@ 1:48 P.M. It was taking too long and the updates were all to apps I don't use on Mini M1.

So I quit app store. ( I hope half downloaded updates aren't hanging around).


The current speculation is that the HDMI signal loss was due to network and security issues

in the miniM1 system, seeing how it effected mini15 via screen sharing connection.


Mini15 is so named because I bought it new in 2015. It has High Sierra running on it.


I hope someone can follow up on this and have some help available regarding it for

future or existing similar issues with HDMI signal loss on Mini with M1 chip and/or Big Sur

JK

Aug 8, 2021 3:42 PM in response to anotherJeff273

I probably have solved the HDMI signal issue:

In System Preferences -> Energy Saver -> Turn Display Off After ( time scale)

I had it set for about 15 minutes. So I set it to 'never'. With possibly two machines

running at the same time and only one monitor, I don't want one machine to shut

off its display. But for future reference, how would one turn the display back on

when it is attached to a third party monitor via HDMI? The presence of mouse

and/or keyboard activity? I have not had to deal with this specific issue before.


I hope this might be helpful to anyone who is hunting for a solution to a similar

issue.

JK

Mac mini with M1 chip and Big Sur HDMI signal ceases?

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