Are you intending to upgrade to Tahoe on Monday? Or to Sequoia or Sonoma? Are you ready to cope with what could go wrong? Here are some tips to help you prepare.
DFU
How to check there’s no hardware problem, then use Restore in DFU mode to completely wipe internal storage, including firmware, and reset the NVRAM.
Working with external bootable disks: how to create and add them, ownership and LocalPolicy, how that can be changed, and what happens with errors and failure.
Some support USB4, others don’t. Some share the controller, others don’t. Some support DFU mode but then can’t be used to create a bootable external disk on Apple silicon.
Recovery reinstall, using an Installer app, or a bootable installer, or with an Apple silicon Mac in DFU mode? What the choices are, and how best to do it.
When should you put your Mac into DFU mode, hook it up to another Mac running Configurator, and revive or restore it?
Is that Mac completely dead due to a severe failure, or could it just be in DFU mode? They aren’t easy to distinguish on most Macs.
Apple silicon Macs are better-equipped to prevent and deal with disaster. Restoring in DFU mode is extremely unusual, and more powerful than anything you can do with an Intel Mac.
If there’s a problem, you may try Recovery mode. What do you do when that proves to be a problem? Solutions for Intel and Apple silicon Macs.
Should you be scared of ‘bricking’ your Mac? Just what does it mean, and what could you do about it? Don’t panic: it’s not a dragon to be slayed.
The Eclectic Light Company 