Apple announced the M1 Mac mini in November 2020, promising 3 times faster CPU speeds, 6 times the GPU performance (with support for 6K displays), and 15 times the machine learning performance over the previous generation. While the performance of the Apple Silicon chip has been praised, the company is reportedly investigating an issue where "pink squares" appear when the new Mac mini is connected to a display.
Multiple threads on Apple's forums have cited an issue where random pink squares appear on the display when the M1 Mac mini is connected via the HDMI port rather than the Thunderbolt. One such thread has over 500 endorsements from users who faced the same issue. The forum post mentions that:
I received my M1 Mac mini on Tuesday and didn't experience any problem until today. Turned it on and noticed some small pink squares moving around my monitor. They would change position as I opened a folder or right clicked on something. After changing the stock wallpaper they disappeared. I also switch my HDMI cable just because, but I've been using this HDMI cable with other devices with no problem what so ever. Hoping it's not a hardware issue as this is a brand new unit.
While the culprit behind the issue is currently unknown, MacRumors has obtained an internal memo, dated February 19, which indicates that Apple is investigating the problem. In the meantime, the following troubleshooting steps have been mentioned in the memo:
- 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
As Apple has not publicly acknowledged the investigation yet, it is unclear as to when a fix will be released. That said, it should be sooner rather than later given that the company is actively looking into it.