How to reset the SMC of a Mac computer, Mac computer reset SMC tutorial

Although mac is a very high-end personal notebook computer, mac will also have failures, such as high-speed fan rotation, abnormal behavior of keyboard backlight, etc., it is very likely that your system management controller smc has appeared There is a problem, so today the editor will come to popular science on how to reset the system management controller smc. Interested users don't miss it!

Functions of SMCs

On Intel-based Mac computers, the SMC manages the following and other low-level functions:

Respond to pressing the power button
Respond to opening and closing of the display lid on a Mac notebook computer
battery management
thermal management
Sudden Motion Sensor (SMS)
Ambient Light Sensing
keyboard backlight
Status Indicator Light (SIL) Management
battery status light
Select external (not internal) video source for some iMac displays
How to tell if you need to reset the SMC

The following symptoms may indicate that the SMC may need to be reset:

The computer fan spins at high speed despite a light computer workload and good ventilation.
The keyboard backlight is behaving strangely.
The status light (if any) is behaving strangely.
The battery light (if present) is behaving strangely (on Mac notebooks with non-removable batteries).
The monitor backlight does not respond properly to changes in ambient light.
Mac doesn't respond when the power button is pressed.
Mac notebooks do not respond correctly to lid opening and closing.
Your Mac goes to sleep or shuts down unexpectedly and you can't turn it back on.
The battery cannot be charged normally.
A MacBook or MacBook Pro cannot be charged through its built-in USB-C port.
A MacBook or MacBook Pro doesn't recognize an external device connected to its built-in USB-C port.
The LED light on the MagSafe power adapter (if present) does not correctly indicate the status of charging activity.
Although the CPU utilization of the Mac is not very high, it is running very slowly.
Macs that support Target Display Mode cannot enter or exit Target Display Mode properly, or enter or exit Target Display Mode unexpectedly.
The backlight around the I/O ports on the Mac Pro (Late 2013) does not turn on when the computer is in motion.

Before resetting the SMC

Before resetting the SMC, try the following steps in order. After each step, test to see if the problem still occurs.
If your Mac isn't responding, press and hold the power button until the computer shuts down. Any data not stored in open applications will be lost. Then, press the power button again to turn on your Mac.
Press Command-Option-Escape to force quit any unresponsive applications.
Choose 苹果 () 菜单 > 睡眠, to put your Mac to sleep. After the computer goes to sleep, wake it up.
Choose 苹果菜单 > " 重新启动" to restart your Mac.
Choose 苹果菜单 > " 关机" to shut down your Mac, then press it again 电源按钮to turn your Mac back on.

If you're using a Mac notebook with power or battery issues, follow these steps:

Unplug the power adapter from the Mac and from the wall outlet, wait a few seconds, then plug it back in.
Choose 苹果菜单 > 关机, then wait for your Mac to shut down.
Remove and reinstall the battery (if removable).
Press the power button again to turn on the Mac.
If the problem is still not resolved, you may need to reset the SMC by following the steps below.
On some keyboards, Option 键it is also marked as Alt.

How to reset the SMC on a Mac laptop

If your Mac notebook is equipped with the Apple T2 Security Chip, please skip this section and go directly to the T2 section.
To reset the SMC on a Mac notebook, first make sure the battery is removable. Most older Mac notebooks have removable batteries. Mac notebooks with non-removable batteries include MacBook Pro (Early 2009 and later), all models of MacBook Air, MacBook (Late 2009), and MacBook (Retina, 12-inch, Early 2015 and later) . Learn more about Mac notebook batteries.

If the battery is not removable:

Choose 苹果菜单 > 关机, then wait for your Mac to shut down.

Press on the left side of the built-in keyboard Shift-Control-Option, and then press 电源the buttons at the same time. Press and hold these keys and the power button 10 秒钟. If your MacBook Pro has Touch ID, the touch ID button is also the power button.

Release all keys.

Press the power button again to turn on the Mac.

If the battery is removable:

Shut down the Mac.

Remove the battery. If you need assistance removing the battery, please contact an Apple Authorized Service Provider or an Apple Retail Store.

Press and hold 电源the button 5 秒bell.

Reinstall the battery.

Press the power button again to turn on the Mac.

How to reset the SMC on a Mac desktop computer

If your Mac desktop computer is equipped with the Apple T2 Security Chip, please skip this section and go directly to the T2 section.

For iMac, Mac mini, Mac Pro, and Xserve, follow the steps below.

Choose 苹果菜单 > 关机, then wait for your Mac to shut down.

unplug 电源线.

wait 15 秒.

Reconnect the power cord.

Wait for 5 秒the clock, then press the button again 电源to turn on the Mac.

For an unresponsive Intel-based Xserve computer, you can shut down locally or using a remote command. You can also press and hold the power button for 5 seconds.

How to reset the SMC on a Mac with the Apple T2 Security Chip

For Mac computers equipped with the Apple T2 Security Chip, follow the instructions below.

Mac desktop computers with the T2 chip

Try the following first:

Choose 苹果菜单 > 关机, then wait for your Mac to shut down.

Press and hold 电源the button 10 秒bell.

Release 电源the button and wait a few seconds.

Press the button again 电源to turn on the Mac.

If the actions above don't resolve the issue, please follow the steps below:

Choose 苹果菜单 > 关机, then wait for your Mac to shut down.

unplug 电源线.

wait 15 秒.

Reconnect the power cord.

Wait 5 seconds, then press the power button again to turn on your Mac.

Mac notebooks with the T2 chip

Try the following first:

Choose 苹果菜Menu > 关机, then wait for your Mac to shut down.

Press and hold 电源the button 10 秒bell.

Release 电源the button and wait a few seconds.

Press the power button again to turn on the Mac.

If the actions above don't resolve the issue, please follow the steps below:

Choose Apple menu > Shut Down, then wait for your Mac to shut down.

Press and hold the right Shift 键, 左 Optionand keys 左 Control 键 for 7 seconds. Your Mac might turn on and display the Apple logo on the display. While continuing to hold down these keys, also press and hold the power button for 7 seconds. If your Mac turned on when you first pressed these keys, it will shut down at this point.

Release all three keys and the power button, and wait a few seconds.

Press the power button again to turn on the Mac.