Kernel Panic

If your Mac restarts on its own and shows "Your computer was restarted because of a problem":

1. Update macOS: This fixes most kernel panics
2. Disconnect external devices: Reconnect one at a time to find the culprit
3. Run Apple Diagnostics: Shut down, then hold the power button. When options appear, press Cmd + D
4. Safe Mode: If it happens repeatedly, boot into Safe Mode to isolate the issue

Apple Diagnostics

Run built-in hardware tests:

1. Shut down your Mac
2. Press and hold the power button until you see startup options
3. Press Cmd + D
4. Follow the on-screen instructions

Reference codes: If you get an error, note the code and look it up at support.apple.com or contact Apple Support.