How to Reset the SMC on an Intel MacBook

If your Intel-based MacBook is exhibiting strange hardware behaviours—such as the battery not charging, the cooling fans spinning at maximum speed while the computer is idle, or the keyboard backlight refusing to turn on—the standard “turn it off and on again” advice rarely works. Instead, you need to reset the System Management Controller (SMC).

The SMC is a dedicated chip on the logic board of Intel Macs that manages low-level hardware functions, including power, thermal management, and LED indicators. Resetting it is a safe and effective troubleshooting step that does not delete any of your personal data.

Note: If you have a modern Mac with Apple Silicon (M1, M2, or M3 chips), your computer does not have an SMC. Simply restarting an Apple Silicon Mac performs a similar hardware reset automatically.

When Should You Reset the SMC?

Apple recommends resetting the SMC only after you have exhausted standard software troubleshooting steps. You should consider an SMC reset if you experience any of the following symptoms:

• The battery charges inconsistently or refuses to charge at all, even when connected to a working power adapter.
• The Mac’s internal fans run at high speed constantly, despite the computer not performing any demanding tasks.
• The keyboard backlight behaves erratically or fails to turn on.
• The MacBook fails to respond when you open or close the lid.
• The computer runs unusually slowly, even with minimal CPU usage.

How to Reset the SMC on a MacBook with a T2 Security Chip

Apple included the T2 Security Chip in MacBook Pro and MacBook Air models released between 2018 and 2020. The reset process for these machines is slightly different from older models.

1. Shut down your Mac completely.
2. Press and hold the physical Power button (which is also the Touch ID sensor) for exactly 10 seconds.
3. Release the power button and wait 5 seconds.
4. Press the power button again to turn the Mac on.

If that simple reset did not resolve the issue, you can perform the full keyboard reset:

1. Shut down your Mac.
2. On the built-in keyboard, press and hold the following three keys simultaneously:
   • Control (on the left side of the keyboard)
   • Option (Alt) (on the left side)
   • Shift (on the right side)
3. Keep holding all three keys for 7 seconds. Without releasing them, press and hold the Power button as well.
4. Keep holding all four keys for another 7 seconds, then release them all at the same time.
5. Wait a few seconds, then press the power button to turn the Mac on.

How to Reset the SMC on an Older MacBook (Pre-2018)

If your MacBook was released before 2018, it likely does not have the T2 chip. As long as the battery is non-removable (which applies to almost all MacBooks made after 2009), follow these steps:

1. Shut down your Mac completely.
2. On the built-in keyboard, press and hold the following three keys simultaneously on the left side of the keyboard:
   • Shift
   • Control
   • Option (Alt)
3. While holding those three keys, press and hold the Power button.
4. Keep holding all four keys for exactly 10 seconds.
5. Release all keys at the same time. If your MagSafe power adapter is connected, the small indicator light on the cable might briefly change colors to indicate the reset was successful.
6. Press the power button to turn your Mac back on.

After the Mac boots up, your hardware symptoms should be resolved. If your battery still refuses to charge or the fans continue to spin aggressively, the issue is likely a physical hardware failure that requires professional repair.