In an internal memo this week, obtained by MacRumors, Apple informed service providers that it is aware of and investigating an issue that may result in "pink squares or pixels" appearing on displays connected to an M1 Mac mini.
This issue has been reported by users across the Apple Support Communities, MacRumors Forums, and Reddit since the M1 Mac mini launched in November, but the exact cause is unclear. Based on comments from affected users, it appears that the issue may be more common when connecting displays via HDMI compared to Thunderbolt.
Apple did not provide a specific timeframe for a fix. The memo was issued on February 19, over a week after the release of macOS Big Sur 11.2.1, which does not appear to address the issue. It is possible that a fix could be readied in time for the release of macOS Big Sur 11.3, which has been in beta testing since February 2.
In the meantime, Apple outlined the following troubleshooting steps:
- Put the Mac mini to sleep
- Wait two minutes and wake the Mac mini
- Unplug the display from the Mac mini, and then plug the display back in
- Adjust the display's resolution in System Preferences > Displays
If the issue reoccurs after restarting the Mac mini, Apple says to repeat the steps above.
There have been various other external display issues with M1 Macs in recent months, ranging from USB-C connection issues to some resolutions being unavailable when using an ultrawide or super-ultrawide display.
/https://forums.macrumors.com/attachments/1733317/)
