Startup disk full, computer won't turn on at all!

Hi, my computer has displayed a “startup disk full” message lately, but I haven’t had time to address it. Now my Mac is out of battery, and it won’t turn on after charging it for a while. What could be wrong with my Mac? Is it caused by the “startup disk full” issue? Can anyone help me?

This may be caused by the “startup disk full”, so you can try starting in Safe Mode. Here are the detailed steps.

  1. Start Safe Mode: Press the power button to turn on your Mac and immediately hold the Shift key. Continue holding the Shift key until you see the Apple logo and progress bar, which indicates that your Mac is entering safe mode.
  2. Log in: If you see the login screen in Safe Mode, enter your password to log in.
  3. Access desktop: Once you’re on the desktop, you may notice the system runs slower. This is because safe mode performs some automatic checks and cleanup.
  4. Clear disk space: Go to About This Mac > Storage > Manage. Here, you can view files taking up space and delete unnecessary files.
  5. Restart: After cleaning up, click the Apple logo and select Restart to boot your Mac normally.