How To Reset PRAM/NVRAM And SMC On Mac

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Most Mac users are familiar with the concept of RAM, or random access memory, and many are probably much too used to running out of it. Two elements of RAM are PRAM (parameter random access memory) and NVRAM (non-volatile random access memory), which appear in PowerPC and Intel Macs respectively.

These elements are responsible for holding information about how a Mac is configured, including date/time, mouse, volume, and various other things. They are powered by a battery independent of the Mac itself, so their information is retained even when the machine is switched off.

SMC stands for System Management Controller, the full name of which offers up a nice analogy for non-technical folks looking to understand what an SMC does. Like an air traffic controller or a train controller, the SMC is responsible for controlling a number of Mac’s functions:

  • Detecting (and responding to) the opening/closing of a laptop lid

  • Analyzing a power button being pressed to determine if it should respond by putting the Mac to sleep or shutting it down completely

  • Managing battery performance and displaying remaining battery life

  • Adjusting fan speed to control the temperature of a Mac

  • Controlling backlighting and detecting ambient light to set appropriate levels

When any of these things go wrong, it can be hugely frustrating. That’s true not only because it can make using your Mac much more difficult, or even impossible, but because the issues it puts out are so random it can make you feel like you’re being haunted!

This article looks at some of the common problems that result from SMC or PRAM/NVRAM malfunctions, as well as how to reset them to solve those problems.

Common PRAM/NVRAM And SMC Issues

First things first, we need to pinpoint whether a PRAM/NVRAM issue or an SMC problem (or neither, for that matter) is what’s causing all the trouble. Without knowing that, there’s no way to find out whether a PRAM reset or SMC reset on MacBook Pro, iMac Pro, or Mac Pro will help.

Let’s start with some of the problems commonly associated with SMC issues as, until you realize what’s going on, they can be some of the most frightening for a typical Mac user:

  • Your Mac doesn’t turn on when you open it

  • The trackpad doesn’t work

  • You can’t connect to WiFi

  • The lights or backlights on your Mac are behaving erratically

  • Your fan is running extremely high, even during non-intensive processes

  • Your computer runs or shuts down slowly

Meanwhile, PRAM/NVRAM problems might cause issues like:

  • Incorrect date or time being displayed

  • Keyboard doesn’t respond as it should

  • Volume doesn’t work correctly

  • Erratic scrolling and mouse-clicking behavior

  • Problems with AirPort

  • Sudden and unexplained shutdowns or problems setting the correct boot volume

That’s a hefty list of potential problems and, while encountering any one of them on their own is unpleasant, your Mac exhibiting multiple items from the list is downright frustrating. But before delving into how to reset PRAM/NVRAM or SMC, it’s wise to take a few steps to isolate other potential causes of these issues.

With CleanMyMac X, for example, you can perform quick and easy scans to see if there’s anything wrong with your hard drives, check for malware, purge cluttered caches, and more. All you need to kick things off is a single click of the Scan button, although you can also manually delve into individual issues if you prefer.

smart scan mac cleanmymac

Resetting PRAM/NVRAM on Mac

PRAM/NVRAM reset is quite a bit easier to do than resetting SMC, so let’s start there. If you’re not sure whether you have PRAM or NVRAM, there’s no need to check manuals or google “what is a PRAM?” to find out.

Regardless of which one your Mac uses, the process to reset PRAM on Mac or perform a NVRAM reset is exactly the same:

  1. Power down your Mac and disconnect all USB devices (except wired keyboards)

  2. Press the power button and hold down ⌘ + Option + P + R immediately after doing so

  3. Hold those keys until your Mac restarts and you hear a second startup chime or, for Macs with a T2 Security Chip, until the Apple logo appears and disappears a second time

  4. Check the Startup Disk, Date/Time, and Display sections of System Preferences to ensure that everything looks the way you want it

That’s all there is to it. You may notice that some of your preferences relating to keyboard layout, mouse tracking, time, and volume have been lost, so you might like to make a note (mental or otherwise) of these if you’re very particular about them.

Easily reset SMC on Mac

There are various ways to complete a Mac reset SMC, depending on the Mac model you have. As SMC reset on MacBook Pros with a removable battery is the easiest, let’s begin from there:

  1. Power down your MacBook

  2. Remove the battery

  3. Press the power button and hold it for five seconds

  4. Reconnect the battery and turn on your MacBook

No removable battery? The process will be a bit different:

  1. Power down your MacBook

  2. Press Shift + Control + Option on the left side of your keyboard, then the power button or Touch ID, and hold them all for 10 seconds

  3. Release all keys and turn on your MacBook

If your MacBook has a T2 Security Chip (i.e. it’s a model from 2018 or later), the process looks different yet again:

  1. Power down your MacBook

  2. Press the power button and hold it for 10 seconds, then restart

  3. If that doesn’t help, press the right Shift key + left Control key + left Option key, then hold them for seven seconds

  4. Release all keys and turn on your MacBook

That lack of consistency (five seconds, seven seconds, 10 seconds, right Shift, left Shift) might seem a bit infuriating when you read all of the different methods together, but it’s not so bad once you’ve determined the MacBook model you have and the steps you need to take.

Reset SMC on Mac Mini, iMac, or Mac Pro

As with MacBooks, there are a couple of different routes on how to reset SMC with other Macs. The one you need to take will vary depending on the age of your Mac. For older (i.e. pre-2018) Macs the process is very simple:

  1. Power down your Mac

  2. Unplug your power lead and wait 15 seconds

  3. Reconnect your power lead and wait another five seconds

  4. Turn on your Mac

For newer Macs with a T2 Security Chip (e.g. an iMac Pro), you’ll need to take the following steps for an SMC reset:

  1. Power down your Mac

  2. Press the power button and hold it for 10 seconds

  3. Release the power button and restart your Mac

  4. If that hasn’t resolved the issue, power down your Mac again

  5. Unplug your power lead and wait 15 seconds

  6. Reconnect your power lead and wait another five seconds

  7. Turn on your Mac

Congratulations: you now officially know how to reset SMC on Mac!

Issues caused by PRAM/NVRAM or your System Management Controller can be pretty scary when you don’t know what’s causing them, but once you figure out what the culprit is, they are not too difficult to deal with. Using software like CleanMyMac X, mentioned above, to monitor the health of your Mac can be helpful for eliminating other possible causes.

Another useful utility for this is iStat Menus because it monitors key indicators like hard drive temperature, memory load, battery cycles, and fan speed. You’ll notice plenty of crossover here if you go back to the list of “symptoms” indicating that PRAM/NVRAM or SMC are causing problems on your Mac. Reset SMC or PRAM/NVRAM to deal with anything flagged up as peculiar by iStat Menus and your Mac will be back to its old self in no time!

istat menus

Setting up the iStat Menus app is only a matter of installing a couple of key components and setting the level of detail you want it to show in the menu bar. It’s definitely worth checking out, as anything that can detect early onset of PRAM/NVRAM and SMC issues is a good thing in our book.

Best of all, both iStat Menus and CleanMyMac X are available for a free trial through Setapp, a platform of more than 150 Mac apps and utilities that can solve even the most difficult technical challenges your Mac can reveal. Try it today and keep the guard on your Mac up by default.

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