Sometimes, for no apparent reason, macs can behave incorrectly: the lights don’t work properly, the volume Settings mess up, the display resolution changes, or they don’t start at all.
Some problems can be resolved by restarting the computer. However, sometimes the SMC, PRAM, or NVRAM need to be reset.
What is SMC in Mac?
The System Management Controller (or SMC) is an Intel-based chip in the Mac. It involves many of the physical parts that run the machine, including LED indicators, keyboards and other peripherals, cooling fans and power buttons. It also plays a role in the behavior of hard drives, the behavior of macs in sleep mode, and power supplies.
When should THE SMC be reset?
The SMC is responsible for many of the functions in the Mac, so it’s worth resetting whenever you find computer hardware behaving in unexpected ways. The following are the recommended symptoms for resetting the SMC:
The battery or status indicator is abnormal
Keyboard backlight doesn’t work properly
The MacBook cannot be turned on when opened
Does the power adapter indicator not reflect what it is doing
Fans run at unusually high speeds, especially under low loads
The trackpad does not work
Your computer cannot connect to Wi-Fi
The target display mode is accidentally turned on or off
Application ICONS will bounce for a long time when opened
Even under low CPU load, your computer runs slowly
Computers shut down slowly
When the Mac fails to start
How do I reset SMC on a Mac
There are several different ways to reset the SMC, depending on the Mac type.
Reset SMC on M1 Mac
No need to reset the SMC on a MacBook or Mac Mini powered by Apple Silicon. Actually, you can’t, because Apple’s chips don’t have a system management controller.
If you encounter any problems that can normally be resolved by resetting the SMC, some users suggest that shutting down the Mac for 30 seconds before rebooting the computer can resolve the problem.
Reset the SMC on an Intel MacBook
To reset the SMC on a MacBook with the Apple T2 security chip (2018 or later models) :
Close the Mac.
Hold down the power button for 10 seconds, then reboot.
If you can fix the problem, shut down the Mac again.
Hold the right Shift key on the left Option key while holding the left control key for 7 seconds.
Hold these keys down while pressing and holding down the power button for 7 seconds.
Release all buttons and wait a few seconds. Now reboot your MacBook.
To reset the SMC on a MacBook with a non-detachable battery (mainly before 2018) :
Close the Mac.
Hold down the Shift key to control and options on the left keyboard. Now hold down the power button (or Touch ID button).
Hold all the keys down for 10 seconds.
Release all buttons and open the MacBook.
To reset the SMC on older macBooks with removable batteries (mainly before 2015) :
Close the Mac.
Remove the battery.
Hold down the power button for 5 seconds.
Reconnect the battery and open the MacBook.
Reset the SMC on an iMac, Mac Mini, or Mac Pro
To reset the SMC on a desktop Mac with a T2 chip (such as an iMac Pro) :
Close the Mac.
Hold down the power button for 10 seconds.
Release the power button, wait a few seconds, and then restart the computer.
If the problem does not go away, shut down the Mac again.
Unplug the power cable.
Wait 15 seconds.
Reconnect the power cable and wait five seconds.
Open your Mac.
What are PRAM and NVRAM in Mac?
PRAM (Parametric Random access Memory) and NVRAM (non-volatile random access memory) hold information about Mac configuration.
This includes aspects such as date and time, as well as desktop, volume, mouse, and other control Settings. These memory areas are powered by small batteries, so these Settings are not lost each time the computer is shut down.
When should YOU reset your PRAM or NVRAM?
Problems with PRAM or NVRAM are usually related to software. The computer may forget certain Settings or may experience connection problems due to memory problems. Try a reset when you experience any of the following symptoms:
Volume does not respond correctly
Boot volume not set (you will see a question mark before the computer starts)
Strange mouse scrolling and click speed
The keyboard is not responding properly
The time zone or clock is incorrect
Display resolution changes or does not change
The airport problem
Computers shut down slowly
How do I reset PRAM or NVRAM on a Mac
If you have an M1 Mac, there is no need to reset the NVRAM. (This process happens automatically when the computer is restarted.)
For older Macs, there is no need to know whether your Mac is NVRAM or PRAM, as the process for resetting both is the same:
Close the Mac.
Press the power button.
Before the gray screen appears, press Cmd, Option, P, and R keys simultaneously.
Press and hold these keys until your computer restarts and you hear the startup sound again.
On macs equipped with the T2 security chip, hold down the button until the Apple logo appears and disappears a second time.
Release the button.
After resetting, some Settings may be lost, such as time, volume, mouse Settings, and keyboard preferences.