We normally try to start a Mac up in Recovery mode when there’s a problem. But when Recovery mode itself proves a problem, what can we do?
Can’t enter Recovery mode
Intel Macs can only enter Recovery and other startup modes when a functional keyboard is connected. If you’re using a wireless keyboard and can’t seem to get your Mac to start up in any of these modes, either use a USB wired keyboard or connect that wireless keyboard to your Mac using its charging lead, which turns it into a USB keyboard.
If normal Recovery fails, you can try its internet or remote version, by starting up with the Command-Option-R keys held. This is notoriously slow, as it first has to download a disk image of the recovery system before running it.
Apple silicon Macs rely on the Power button to enter Recovery and other startup modes. This simply involves pressing and holding the Power button until the display shows that options are being loaded. If that doesn’t happen, try Fallback recovery as detailed below. These may seem difficult at first, but are really far simpler. There is no internet or remote recovery, though.
Keyboard or language problems
At the top right of each screen in Recovery mode is a keyboard menu where you can select your preferred layout.
Apple silicon Macs also let you pair or repair Bluetooth input devices, including keyboard, mouse and trackpad. This is accessed from the initial Options screen once Recovery has loaded. To pair devices, press the Power button three times in slightly less than three seconds. If you press too fast, or leave more than a second between presses, this may not work. If you’ve got it just right, the Bluetooth Setup Assistant should help you pair the device you want.
When the main Recovery options window has loaded, you should see a Wi-Fi icon at the top right of the screen. If that doesn’t show a decent signal, use that menu to join the right network.
Run hardware diagnostics
On Intel Macs, you have to start up in Diagnostics using the D or Option-D keys held. The single D key runs Diagnostics from your Mac, while Option-D is your fallback if that doesn’t work, as a disk image will be downloaded from Apple’s servers, then run.
Apple silicon Macs here, and only here, use a keystroke command, although it’s not held during startup. To enter Diagnostics, at the first Options screen of Recovery hold Command-D until you’re told that Diagnostics is loading, then select your language, and the Diagnostics Loader app should load and offer to run diagnostics. If that doesn’t work, you’ll be prompted to Restart to Diagnostics using its menu, and so to try again. If that doesn’t succeed, start up in Fallback Recovery and try there.
Rather than offering an internet Recovery mode, Apple silicon Macs usually have local Fallback Recovery available. This is normally installed in a hidden partition/container on the Mac’s internal SSD. Entering this mode is something of a knack: press the Power button twice in rapid succession, and with the second press keep the button pressed in until you see Options are loading.
Fallback Recovery is identical in every respect to normal Recovery, except for one: Startup Security Utility can’t be used to change boot security in most cases.
Restore in DFU mode
Apple silicon Macs have one last and ultimate fallback: if the worst comes to the worst, you can start the Mac up in DFU mode, connect it to another Mac running Apple Configurator 2, and from there you can restore its firmware and software completely. This will leave the Mac in as-new condition, as if it has just been unboxed for the first time. All user data is erased in this process, so you’ll then have to migrate from your most recent backup, when you have started your restored Mac up and personalised it. This is detailed fully in the Help book for Configurator, and requires a USB-C cable, not Thunderbolt, to connect the two Macs. If this seems too much for you to attempt, Apple stores and authorised service providers should be able to do this while you wait.
Intel: An A to Z of keys and keyboards: Startup and login, and Apple
Apple silicon: An illustrated guide to Recovery on Apple silicon Macs, and Apple