3 ms·

It looks like the I/O board is the issue: https://discussions.apple.com/thread/252033190?answerId=253881862022#253881862022 https://discussions.apple.com/thread

• mmastrac 6y ago
  This will be an interesting postmortem. Perhaps the EFI firmware contained incompatible firmware for this HDMI chip? Or maybe removing it bypasses a buggy bit of firmware?
  • tpush 6y ago
    Speaking of UEFI, does anyone know if Apple still uses UEFI in the DTK or M1 chip Macs?
    • Gaelan 6y ago
      I believe folks have said no.
  • madaxe_again 6y ago
    I’d assume it’s different in the 15” late 2013 machines, as I upgraded today without issue - although there was about a five minute interlude of a completely black screen, during which I can only assume it was doing whatever it does to the IO board that bricks the 13” models.
• spuz 6y ago
  The poster says the update somehow broke their IO IC. That seems unlikely. It's more likely that the update includes new firmware for that chip which contains a bug. In theory, when Apple identify the cause they can update their software so this won't happen for future upgrades. In the meantime, I'm sure they can offer compensation to those with bricked devices who can choose to either put that towards a new computer or send it in for repair.