In an internal memo this week, obtained by MacRumors, Apple informed service providers that it is aware of and investigating an issue that could result in “pink squares or pixels” appearing on monitors connected to a Mac mini M1.
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This issue has been reported by users in the Apple Support Communities, MacRumors and Reddit forums since the M1 Mac mini was released in November, but the exact cause is unclear. Based on feedback from affected users, it appears that the problem may be more common when connecting monitors via HDMI compared to Thunderbolt.
Apple did not provide a specific deadline for the correction. The memo was issued on February 19, more than 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 fix will be prepared in time for the release of macOS Big Sur 11.3, which has been in beta testing since February 2.
In the meantime, Apple has described the following troubleshooting steps:
- Put your Mac mini to sleep
- Wait two minutes and wake up your Mac mini
- Disconnect the screen from the Mac mini, then connect it again
- Adjust the screen resolution in System Preferences> Monitors
If the problem recurs after restarting your Mac mini, Apple recommends repeating the steps above.
There have been several other external display issues with Macs M1 in the past few months, ranging from USB-C connection issues to some unavailable resolutions when using an ultra or super ultra large screen.