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Scattered reports suggest an EFI firmware issue may be bricking some Macs when updating to Catalina

macOS Catalina
macOS Catalina (Image credit: iMore)

What you need to know

  • There are some reports that updating to Catalina is causing bricking with some Macs
  • The issue seems to be a result of an EFI firmware update.
  • Initial reports suggest the issue is only affecting a very small number of devices.

A report via 9to5Mac suggests that a very small number of Mac users may be experiencing bricking when updating to macOS Catalina.

According to the report:

There are forum reports of the update to macOS Catalina resulting in some Macs becoming non-responsive, with some indication that an update to the EFI firmware may be responsible … There are multiple threads on Apple's support forums, with most reports appearing similar in nature.

Many of the reports seem to concern older Macs from 2014 and 2015. All the reports tell the same story of upgrading to Catalina, only to be greeted by Apple's black screen and the "?folder" icon. One user reported that an unofficial service center directly programmed the EFI with a special tool, which fixed the problem. This would seem to confirm the suggestion from several of the reports that corruption of the EFI firmware may be to blame.

At this stage, there are a very small number of reports, so whilst it no doubt seems to be an issue, the scale of the problem seems to be very limited at this juncture.

Stephen Warwick
Stephen Warwick

Stephen Warwick has written about Apple for five years at iMore and previously elsewhere. He covers all of iMore's latest breaking news regarding all of Apple's products and services, both hardware and software. Stephen has interviewed industry experts in a range of fields including finance, litigation, security, and more. He also specializes in curating and reviewing audio hardware and has experience beyond journalism in sound engineering, production, and design.

Before becoming a writer Stephen studied Ancient History at University and also worked at Apple for more than two years. Stephen is also a host on the iMore show, a weekly podcast recorded live that discusses the latest in breaking Apple news, as well as featuring fun trivia about all things Apple.

3 Comments
  • Maybe they will also fix the onboard diagnostics the newer EFI broke too!
  • https://discussions.apple.com/thread/250285425?answerId=251506575022
  • I’m one of these users. Perfectly good healthy mac before the update. Machine rebooted during the update and that was the end of it. Flashing folder icon. I no longer get the Apple logo of chimes on power on. Everything has been reset my Genius Bar can’t boot from usb or anything to resurrect my mac. Apple store told me they would call back a couple of days later. 1 week on no call. Followed up but can never get through to the store to get an update. It’s a 2 hour round trip to get to the store too so it’s not an easy option to just go in. Very disappointed with this.