A 15 inch MacBook Air M4 that does not finish starting, shows a question mark, a prohibitory sign or loops, is fixed from macOS Recovery, and Apple silicon Macs enter it differently from Intel ones. Shut the Mac down, then press and hold the power button until the startup options window appears, then choose Options and Continue. From there you can use Disk Utility to run First Aid on the startup disk, reinstall macOS without erasing, or restore from a Time Machine backup.
The checks in more detail
Apple's page for a Mac that does not start up all the way describes what each screen means. If First Aid reports errors it cannot fix, back up what you can with the Terminal in Recovery or Share Disk, then reinstall. If Recovery itself does not open, the Mac may need an Apple-supported revive or restore using another Mac and a USB-C cable with Apple Configurator.
Keep the Mac plugged in throughout. Check Find My to see whether the Mac is locked by Activation Lock, which blocks a restore. Before erasing anything, try Safe Mode: on an Apple silicon Mac hold the power button until startup options appear, select the disk, then hold Shift and choose Continue in Safe Mode; if the Mac starts normally in Safe Mode, a login item or extension is the cause and removing it fixes the loop. Keep notes of what changed before the problem. Keep a bootable backup or a current Time Machine backup before any major macOS update, since a failed update is the most common cause of a Mac that will not start; Time Machine on an external drive lets you restore in an hour even if the internal disk is damaged, and iCloud holds your documents separately.
Differential
Likely causes of “Apple MacBook Air 15-inch is stuck at startup, automatic repair or recovery”, and how to tell them apart
- 1
A damaged startup volume
What separates it Question mark or loop
How to confirm Disk Utility, First Aid
- 2
A failed macOS update
What separates it The Mac stops at the logo
How to confirm Reinstall macOS from Recovery
- 3
A corrupted system
What separates it It does not boot normally
How to confirm Restore from a Time Machine backup
- 4
Recovery unavailable
What separates it Power hold does not open options
How to confirm Use another Mac to revive or restore
- 5
Activation Lock
What separates it A restore asks for an Apple Account
How to confirm Sign in with the original account
Before you touch a setting
Record this first — changing settings destroys the evidence
- What the screen shows
- Whether Recovery opens
- Whether you have a Time Machine backup
- The macOS version before the problem
Try in this order
0 of 8 completedOpen Recovery
ReversibleShut down, then hold the power button until Options appears.
Run First Aid
ReversibleDisk Utility, select the startup disk, First Aid.
Reinstall macOS
ReversibleChoose Reinstall macOS without erasing.
Restore from backup
ReversibleIf you have Time Machine.
Use another Mac to revive
ReversibleIf Recovery does not open.
Check Activation Lock
ReversibleBefore a restore.
Try Safe Mode
ReversibleFrom startup options, select the disk, hold Shift and choose Continue in Safe Mode.
Remove recent login items and extensions
ReversibleIf Safe Mode works, open System Settings, General, Login Items and remove recent ones.
Model-specific
What is true of this model and not of its siblings
- Apple silicon Recovery
- It opens with a power hold, not keys.
- Revive
- A second Mac can restore the firmware.
- Safe Mode
- It loads only the essentials.
- Login items
- A bad one can stop normal start-up.
Stop boundary
When this stops being a self-service repair
- !If Recovery will not open, contact Apple Support
- !If First Aid fails repeatedly, ask Apple
- !Back up before erasing
Evidence ledger
Sources behind this answer
Exact questions
Common questions
How do I open Recovery on an M4 Mac?+
Hold the power button until Options appears.
Will reinstalling erase my files?+
Not if you choose to reinstall without erasing.
What is First Aid?+
A repair tool in Disk Utility.
What if Recovery does not open?+
Use another Mac to revive it.
What is Safe Mode?+
A minimal start-up.
How do I enter it on an M4 Mac?+
Through startup options with Shift.