Unusual Video Problem on 2018 Mac Mini When Rebooted

Whenever I reboot my 2018 Mac Mini, I either lose video when it comes back up or the video is standard def instead of widescreen with a large, vertical black band on the left hand side of the monitor. The only thing that seems to fix it in both cases is unplugging and replugging the HDMI cable. Sick of doing that and wondering if anyone has a fix? Thanks!

The first thing I’d try would be another cable, making sure you get one that matches the Mini’s specs.

1 Like

I don’t think Apple understands how to build Macs without built in displays. My 2018 Mac mini will not see my screen unless it is fully on at the time the Mac boots. If the screen is in power save mode then sometimes unplugging the cable and replugging will get it recognised, but other times it requires another reboot with the screen on. This is particularly annoying seeing my LG monitor has like a 5 second timeout for power saving mode. All of this makes software updates a chore as I have to sit there to keep the screen alive across any reboots.

Also, sometimes when the screen is detected, it is switched into some HDR mode that I don’t even understand (there are no OSD settings for it) and I have to (quickly!) turn the monitor off and on to get it back to normal.

The only good news is the random spontaneous reboots caused by (I assume) Catalina have now progressed to spontaneous shutdowns, so at least I can start the Mac from cold with the screen on.

I’m looking forward to a new Apple Silicon iMac or maybe a laptop. I might keep the mini as a server, but the idea of it being headless worries me!