First: Intel or Apple silicon?
To find out which method to follow, go to the Apple menu › About This Mac. If the window shows Chip (Apple M1, M2…), it’s a Mac with Apple silicon. If it shows Processor followed by an Intel name, it’s an Intel-based Mac.
For the SMC, you also need to know whether your Intel Mac has an Apple T2 chip. According to Apple, this applies to MacBook Pro and MacBook Air models released from 2018 to 2020 (except the M1 models), the 2020 27-inch iMac with Retina 5K display, the iMac Pro, the 2018 Mac mini and the 2019 Mac Pro.
When to reset them
- NVRAM (or PRAM): this is a small area of memory that stores certain settings, such as sound volume, display resolution, startup disk and time zone. It’s worth resetting it if one of these settings keeps reverting, even though you’ve set it correctly in System Settings.
- SMC (System Management Controller): it manages power, battery charging, fans, sensors and indicator lights. Apple recommends resetting it when the battery won’t charge, the Mac won’t turn on, the fans are spinning fast, the laptop is overheating or the built-in camera isn’t working.
Resetting the NVRAM (PRAM)
This procedure only applies to Intel-based Macs. Apple states that it does not apply to Macs with Apple silicon and isn’t needed on them.
Shut down your Mac
Go to the Apple menu and choose Shut Down.
Turn it on and hold Option, Command, P and R
Press the power button, then immediately press and hold the four keys Option, Command, P and R.
Release after about 20 seconds
During this time, the Mac may appear to restart: you might hear the startup sound more than once or see the Apple logo appear more than once.
Check your settings
Once the Mac has started up, open System Settings to check any settings that may have been reset (volume, resolution, startup disk, time zone) and adjust them if necessary.
Resetting the SMC
Intel MacBook without T2 chip (up to 2017)
Shut down your Mac
Go to the Apple menu and choose Shut Down.
Hold the left Shift, Control and Option keys
On the built-in keyboard, press and hold the Shift, Control and Option (Alt) keys on the left-hand side of the keyboard.
Add the power button for 10 seconds
Without releasing the three keys, press the power button and keep everything held down for 10 seconds.
Release and turn back on
Release all the keys, then press the power button to turn your Mac back on.
MacBook with T2 chip (2018 to 2020)
Apple recommends starting with a simple test: with your Mac shut down, press and hold the power button (or Touch ID) for 10 seconds, release it, wait a few seconds, then turn the Mac back on. If the problem persists, follow the steps below.
Shut down your Mac
Go to the Apple menu and choose Shut Down.
Hold left Control and Option, right Shift
On the built-in keyboard, press and hold Control (left), Option (Alt) (left) and Shift (right) for 7 seconds. Your Mac may turn on.
Add the power button for 7 seconds
Without releasing these keys, also press the power button and keep everything held down for a further 7 seconds. If the Mac had turned on, it will turn off.
Release and turn back on
Release all the keys, wait a few seconds, then press the power button to turn your Mac back on.
iMac, Mac mini, Mac Pro (Intel)
With or without a T2 chip, the method is the same: shut down your Mac and unplug the power cable. Wait 15 seconds, plug it back in, wait another 5 seconds, then press the power button.
Mac with Apple silicon
Make sure your Mac is plugged in, then go to the Apple menu and choose Restart (or Shut Down, then turn it back on). According to Apple, the SMC then resets automatically: no further steps are needed.
Sources: Apple, Reset NVRAM on your Mac and How to reset the SMC of your Mac.
If the problem comes back
A reset fixes a temporary glitch. If the fault comes back or nothing changes, a component is probably to blame:
- Battery not charging: the charger, the charging port, the battery or the logic board could be at fault. Our article MacBook not charging helps you work out which one, and here you’ll find the right battery for your model.
- Mac won’t turn on: follow the checks in our article MacBook won’t turn on.
- Fans running at full speed: see our article fan running at full speed. If the fan is at fault, you’ll find the right fan for your model.
- Keyboard no longer lights up: see our article on faulty keyboard backlighting.
- Logic board: if the problem still isn’t solved, even with a new part, you’ll generally need to replace the MacBook’s logic board.
Find the part for my Mac
Not sure which model you have? Quickly identify the parts you need for this repair without making a mistake.
Need help with the repair? We offer tutorials to guide you step by step through replacing the part. Our team of technicians is also on hand if you need advice.
Frequently asked questions
Does resetting the NVRAM or SMC delete my files?
No. The NVRAM only contains settings (volume, resolution, startup disk, time zone), which you may need to set again. The SMC manages the hardware. Your files and apps are not affected.
How do I reset the NVRAM on a Mac with Apple silicon?
You don’t need to do anything. Apple states that this procedure does not apply to Macs with Apple silicon and isn’t needed on them.
I can’t hear the startup sound while resetting the NVRAM. Is that a problem?
No. Apple only says that the Mac may appear to restart: the startup sound may play more than once or the Apple logo may appear more than once, but this doesn’t always happen. Simply release the keys after about 20 seconds.
My Mac doesn’t respond to Option + Command + P + R. Why?
On a laptop, use the built-in keyboard if possible. With an external keyboard, wait a few seconds for the Mac to recognise it, and ideally use a wired keyboard designed for Mac.
Does resetting the SMC reset the NVRAM?
No. Apple states that resetting the SMC does not affect the NVRAM or PRAM: they are two separate procedures.
