How to Fix a Mac That Won't Turn On

Step-by-step guide to diagnose and fix a Mac that won't power on. Check power, reset SMC, test hardware components, and restore functionality.

1. Check the power connection and cable. Verify the power adapter is firmly connected to both the wall outlet and your Mac. Try a different wall outlet to rule out electrical issues. For MacBooks, ensure the charging cable isn't damaged and the charging port is free of debris. Look for the charging indicator light on MagSafe adapters.
2. Perform a force restart. Press and hold the power button for 10 seconds to force shut down any processes. Release the button, wait 5 seconds, then press the power button once to start up. This clears temporary system states that might prevent normal startup.
3. Reset the System Management Controller (SMC). For MacBooks with T2 chips or Apple silicon: shut down, press and hold the power button for 10 seconds, release and wait 5 seconds, then restart. For Intel MacBooks without T2: shut down, press Shift-Control-Option on the left side plus the power button for 10 seconds, release all keys, then restart. For desktop Macs: unplug power for 15 seconds, then reconnect.
4. Test with external displays and peripherals disconnected. Disconnect all external devices including displays, USB devices, and Thunderbolt accessories. Leave only the power adapter connected. Attempt to start the Mac. Faulty peripherals can sometimes prevent startup by drawing too much power or causing bus conflicts.
5. Check for signs of life. Look for any indicators that the Mac is receiving power: fan noise, drive sounds, LED indicators, or screen backlight. Listen carefully for startup chimes or error beeps. Even if the screen stays black, these signs indicate the logic board is functional and the issue may be display-related.
6. Attempt Safe Mode startup. Press and hold the power button, then immediately press and hold Shift when you hear the startup chime or see the Apple logo. Keep holding Shift until you see the login screen. Safe Mode loads only essential system files and can bypass software conflicts preventing normal startup.
7. Run Apple Diagnostics. Turn on your Mac and immediately press and hold D until Apple Diagnostics starts. This built-in tool tests hardware components and reports any failures. Follow the on-screen instructions and note any error codes that appear. The test takes 2-5 minutes to complete.