Apple Mac mini M1 has an odd bug causing pink squares to appear on monitor screen

Apple Mac mini (M1, 2020)
(Image credit: Future)

Apple’s Mac mini with the M1 processor has run into a pretty weird sounding bug, where pink squares (or pixels) appear on the monitor screen it’s connected to for no apparent reason.

Apple is aware of this problem, and indeed investigating the cause of the issue, according to an internal memo sent to service providers (as reported by MacRumors).

As the report notes, the problem with pink squares popping up on an external display has been complained about across not just the MacRumors forum in the past – since the new M1-powered Mac mini was launched, in fact – but also elsewhere online such as Reddit and Apple’s own support forum. The intruding squares may be more prevalent when using an HDMI cable rather than Thunderbolt.

There are also scattered reports of green squares (see this Reddit thread) or even black ones, as well as the pink squares (or dots). Swapping out to another HDMI cable doesn’t appear to make a difference, although changing your wallpaper might, at least going by other reports.

Fix in the pipeline?

Sadly, the Apple memo doesn’t give us any clue as to when a fix might be expected, but seeing as the Mac maker is seemingly aware of the issue, we can keep our fingers crossed that a solution might be delivered in the near future.

What Apple did provide, though, was a (rather clunky) workaround to banish the squares, which is as follows:

  • 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

This is seemingly a temporary fix, as Apple notes if the squares or dots make their presence known again, users should simply repeat the above steps. Which will obviously get a bit tiresome – so once again, let’s hope the fix is inbound sooner rather than later.

Trying the other mentioned potential workaround of changing wallpaper is clearly worth a shot, too, and represents a far more convenient countermeasure – if it works, that is.

Darren is a freelancer writing news and features for TechRadar (and occasionally T3) across a broad range of computing topics including CPUs, GPUs, various other hardware, VPNs, antivirus and more. He has written about tech for the best part of three decades, and writes books in his spare time (his debut novel - 'I Know What You Did Last Supper' - was published by Hachette UK in 2013).