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Anmoumi

macrumors newbie
Original poster
Mar 30, 2021
1
0
Good day!

Sorry if my English is not on a good side.

I have Mac Mini late 2014, macOS Mojave. Using Samsung screen with HDMI cable bought separately and has worked well for over a year.

Yesterday after turning my Mac on, screen started flickering. I could see process working and log in screen appearing, but couldn't do anything as it turned black every other second.
Managed to fix it by adjusting HDMI cable - at least I think it was that.

Then today turned Mac on and same issue. This time adjusting cables did not work, had to reset NVRAM after forcing Mac shut. Tried restarting and everything worked. I was away from home for few hours and always turn everything off. Now when turning Mac on, same issue. This time NVRAM didn't help first time, had to do it twice. Also tried SMC reset, but that didn't seem to work at all.

Was wondering if it's related to my screen as it kept flickering even when I turned Mac Mini off, but that doesn't make sense as when turned it on first, it did not flicker. Flickering started after turning on Mac Mini as well and then it screen continued doing it, no matter if Mini was on or not.

Any advice or ideas what is causing this? As screen seemed to start flicker only after turning on Mac, but continued doing it even after had to shut Mac down throguh power button, then issue is somehow related to Mini?
Strangely shutting down after fixing this and then turning back on right away does not produce this problem, but after using Mac, turning off and back after few hours causes it to come back.
 
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