In an internal memo this week, obtained by MacRumors, Apple informed service providers that they are aware of and are investigating an issue that could result in “pink squares or pixels” appearing on screens 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 was released in November, but the exact cause is unclear. Based on comments from affected users, it seems that the problem may be more common when connecting monitors via HDMI compared to Thunderbolt.
Apple did not provide a specific time frame for a solution. The note was released on February 19, over a week after the release of macOS Big Sur 11.2.1, which does not seem to solve the problem. It is possible that a solution can be prepared in time for the release of macOS Big Sur 11.3, which has been in beta testing since February 2.
Meanwhile, Apple outlined the following troubleshooting steps:
- Put your Mac mini to sleep
- Wait two minutes and remove the Mac mini
- Disconnect the monitor from the Mac mini, and then reconnect the monitor
- Adjust the screen resolution in System Preferences> Monitors
If the issue persists after restarting your Mac mini, tell Apple to repeat the steps above.
There have been various other external display issues with M1 Macs in recent months, ranging from USB-C connectivity issues to some resolutions that are not available when using an ultra-wide or super-wide display.