How to reset NVRAM on your Mac

Learn about your Mac computer's NVRAM, when it might need to be reset, and how to reset it.

What is NVRAM?

NVRAM is "non-volatile random-access memory," a small amount of your computer’s memory that stores certain settings in a location that macOS can access quickly. The settings that are stored in NVRAM depend on the type of Mac you're using and the types of devices connected to it.

Information stored in NVRAM can include:

  • Speaker volume
  • Screen resolution
  • Startup disk selection
  • Recent kernel panic information, if any

If you experience issues related to these features, resetting the NVRAM can help. For example, if your Mac starts up from a startup disk other than the one you've specified in Startup Disk preferences, or if a question mark icon appears briefly when your Mac starts up, you might need to reset the NVRAM.

How to reset NVRAM

Follow these steps to reset your Mac computer's NVRAM.

If you have a late-2016 MacBook Pro, the steps are slightly different. Skip to the next section for instructions.

  1. Shut down your Mac.
  2. Find Command (⌘), Option, P, and R on your keyboard.
  3. Turn on your Mac.
  4. Press and hold the Command-Option-P-R keys immediately after you hear the startup sound.
  5. Hold these keys until the computer restarts and you hear the startup sound for a second time.
  6. Release the keys.

After resetting NVRAM, you might need to reconfigure settings for speaker volume, screen resolution, startup disk selection, and time zone information.

If issues related to these features continue on a desktop Mac (like an iMac, Mac mini or Mac Pro), its logic board battery might need to be replaced. The logic board battery on desktop computers helps retain NVRAM settings when your Mac is unplugged. You can take your Mac to an Apple Store or Apple Authorized Service Provider to replace the battery on the logic board.

How to reset NVRAM on late-2016 MacBook Pro models

Follow these steps to reset your Mac computer's NVRAM if you have a MacBook Pro (15-inch, Late 2016), MacBook Pro (13-inch, Late 2016, Four Thunderbolt Ports), or MacBook Pro (13-inch, Late 2016, Two Thunderbolt Ports).

  1. Shut down your Mac.
  2. Find Command (⌘), Option, P, and R on your keyboard.
  3. Turn on your Mac.
  4. Press and hold the Command-Option-P-R keys immediately after you turn on your Mac.
  5. Hold these keys down for at least 20 seconds to ensure that your Mac completes the process correctly.
  6. Release the keys.

After resetting NVRAM, you might need to reconfigure settings for speaker volume, screen resolution, startup disk selection, and time zone information.

Learn more

On older Mac computers, similar information was stored in Parameter RAM (PRAM). Resetting NVRAM on Intel-based Macs using the same key combination is like resetting PRAM.

Power-related settings can be controlled by the System Management Controller (SMC) on your Mac. If you're experiencing issues with powering on your computer, sleep, wake, charging your Mac notebook battery, or other power-related symptoms, you might need to reset the SMC instead.

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