How to Reset SMC on Mac

What Causes This?

The System Management Controller, or SMC, is a low-level chip in some Intel-based Macs that controls power, battery charging, fans, sleep, and other hardware functions. If it gets stuck or misreads hardware states, your Mac may act strangely even when macOS itself is fine. This usually happens after power issues, battery problems, overheating, failed sleep/wake cycles, or certain hardware changes. Keep in mind that Apple silicon Macs do not use a separate SMC reset in the same way.

Common Symptoms

• Fans run loudly all the time for no clear reason
• Battery will not charge properly or the charging light behaves oddly
• Mac will not turn on, sleep, wake, or shut down correctly
• Keyboard backlight or status lights act unpredictably
• Performance feels unstable after power or thermal issues

How to Fix It Manually

1. Check whether your Mac supports an SMC reset

   • SMC resets apply mainly to Intel-based Macs.
   • If you have an Apple silicon Mac (M1, M2, M3, or newer), there is no separate SMC reset procedure. Instead, shut the Mac down, wait 30 seconds, then turn it back on.
   • To check your Mac type, click the Apple menu > About This Mac.

2. Shut down your Mac completely

   • Click the Apple menu > Shut Down.
   • Wait until the screen is fully black and the Mac is no longer making fan noise.

3. Reset the SMC on a MacBook with a non-removable battery

   • This covers most Intel MacBooks from recent years.
   • On the built-in keyboard, press and hold:
     • Shift + Control + Option on the left side
     • and the Power button at the same time
   • Hold all four keys for 10 seconds.
   • Release all keys, then press the Power button again to turn on the Mac.

4. Reset the SMC on an older MacBook with a removable battery

   • Shut the Mac down.
   • Remove the battery.
   • Press and hold the Power button for 5 seconds.
   • Reinsert the battery, then press Power to start the Mac.

5. Reset the SMC on an Intel desktop Mac

   • This includes some iMac, Mac mini, and Mac Pro models.
   • Shut the Mac down.
   • Unplug the power cord.
   • Wait 15 seconds.
   • Plug the power cord back in.
   • Wait 5 seconds, then press the Power button to start the Mac.

6. Test the issue after startup

   • Check whether charging works normally.
   • Listen for fan behavior.
   • Try sleep, wake, shutdown, and brightness controls.
   • If the problem remains, restart once more and install any available macOS updates from Apple menu > System Settings > General > Software Update.

7. If it still does not help, look for hardware or software causes

   • Faulty chargers, bad batteries, overheating, and damaged sensors can mimic SMC issues.
   • If your Mac still will not power on or charge correctly, contact Apple Support or an authorized repair provider.

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