How do you reset your Mac's PRAM, NVRAM, and SMC to fix hardware problems?

1 What are PRAM, NVRAM, and SMC?

PRAM stands for Parameter Random Access Memory, and NVRAM stands for Non-Volatile Random Access Memory. They are small amounts of memory that store certain settings and preferences for your Mac, such as startup disk, time zone, volume, screen resolution, and keyboard layout. SMC stands for System Management Controller, and it is a chip that controls various functions related to your Mac's power, cooling, battery, fans, lights, and sensors. Resetting these components can help resolve issues that affect your Mac's hardware or system functionality.

2 How to reset PRAM and NVRAM?

To reset PRAM and NVRAM, you need to restart your Mac and hold down four keys at the same time: Option, Command, P, and R. You'll hear the startup sound once, and then again after about 20 seconds. Release the keys after the second sound, and your Mac will boot normally. This will clear the PRAM and NVRAM settings and restore them to their default values. You might need to adjust some of them manually afterwards, such as your time zone or volume.

3 How to reset SMC?

To reset SMC, the method depends on whether your Mac has a removable battery, a non-removable battery, or a T2 security chip. If your Mac has a removable battery, you need to shut down your Mac, remove the battery, and press and hold the power button for 5 seconds. Then, reinsert the battery and turn on your Mac. If your Mac has a non-removable battery, you need to shut down your Mac, plug in the power adapter, and press and hold the Shift, Control, Option, and power buttons for 10 seconds. Then, release the keys and turn on your Mac. If your Mac has a T2 security chip, you need to shut down your Mac, plug in the power adapter, and press and hold the power button for 10 seconds. Then, release the power button and wait for a few seconds before turning on your Mac. This will reset the SMC settings and fix any power or thermal issues.

4 When to reset PRAM, NVRAM, and SMC?

You don't need to reset PRAM, NVRAM, and SMC regularly, as they usually work fine without any intervention. However, if you experience any issues such as a Mac that won't start up or shut down properly, a display, sound, keyboard, or mouse behaving strangely, an abnormal battery, fan, or temperature, slow or erratic performance, or incorrect date and time settings, then resetting them may be a good troubleshooting step.

5 What are the risks of resetting PRAM, NVRAM, and SMC?

Resetting PRAM, NVRAM, and SMC is generally safe and easy to do, and it won't erase any of your personal data or files. However, there are some potential risks to be aware of before doing it, such as losing customized settings or preferences, encountering compatibility issues with third-party devices or software, voiding your warranty or AppleCare if you open your Mac to remove the battery, and damaging your Mac if done incorrectly or with the wrong keys or buttons. Therefore, it’s important to backup your data before resetting PRAM, NVRAM, and SMC and to follow the instructions carefully. If unsure of how to do it or resetting them doesn’t solve the problem, contact Apple support or a professional computer repair service.

6 Here’s what else to consider

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