How to reset the macOS NVRAM/PRAM to fix display, sound, and startup issues on your Mac

Summary

This guide helps you troubleshoot and resolve: How to reset the macOS NVRAM/PRAM to fix display, sound, and startup issues on your Mac. Follow the steps below to fix the issue.

Common Causes

Your Mac stores certain settings in a small memory area called NVRAM (Non-Volatile Random-Access Memory), also known as PRAM (Parameter RAM) on older Intel-based Macs. This includes details like display resolution, sound volume, startup disk selection, time zone, and recent kernel panic information. If any of these settings behave oddly or won't stick after a restart, resetting the NVRAM/PRAM is a safe and effective first step before diving into deeper troubleshooting.

What NVRAM/PRAM Controls

• Display resolution, brightness, and colour profile
• Sound volume and headphone settings
• Startup disk selection
• Time zone and system clock behaviour
• Recent kernel panic log information (used by Apple Diagnostics)

Reset NVRAM/PRAM on an Intel-Based Mac

1. From the Apple menu, choose Shut Down and wait for your Mac to power off completely.
2. Press the power button to turn your Mac back on.
3. Immediately press and hold the following four keys together: Option + Command + P + R.
4. Keep holding the keys for about 20 seconds. On Macs that play a startup chime, you can release the keys after the chime sounds a second time. On Macs without a startup chime (such as those released from 2016 onwards), release the keys after about 20 seconds, or when you see the Apple logo appear and disappear a second time.
5. Release the keys and allow your Mac to finish starting up.
6. Open System Settings (or System Preferences on older macOS versions) and reconfigure any settings that may have been reset, such as sound volume, display resolution, or startup disk.

Reset NVRAM on an Apple Silicon Mac

Apple silicon Macs (M1, M2, M3, M4 and later) don't use the traditional key combination. Use one of the methods below instead.

Method 1: Use macOS Recovery

1. From the Apple menu, choose Shut Down.
2. Wait for your Mac to fully power off (the screen goes black and all lights are off).
3. Press and hold the power button.
4. Keep holding the power button until you see "Loading startup options" appear on the screen.
5. Click Options, then click Continue.
6. Once macOS Recovery has loaded, choose Utilities > Terminal from the menu bar.
7. Type nvram -c and press Return.
8. Close Terminal, then choose Apple menu > Restart from the menu bar.

Method 2: Use Terminal While Logged In

1. Open Terminal from Applications > Utilities.
2. Type sudo nvram -c and press Return.
3. Enter your administrator password when prompted and press Return.
4. Restart your Mac from the Apple menu.

After the Reset

Once your Mac restarts, check that the original issue has been resolved. You may also need to reconfigure the following settings, as they often return to their defaults:

• Sound output volume and balance
• Display resolution and brightness
• Time zone
• Startup disk (set via System Settings > General > Startup Disk)
• Custom keyboard or mouse settings

Troubleshooting

The Key Combination Doesn't Seem to Work

• Confirm whether your Mac is Intel-based or Apple silicon. Click the Apple menu > About This Mac to check the chip listed.
• Make sure you are pressing the keys immediately after pressing the power button, not after the Apple logo appears.
• Try a wired or external keyboard if you're using a Bluetooth keyboard, as Bluetooth may not be active early in the boot process.
• Ensure you are holding Option, Command, P, and R all at the same time.

The Issue Returns After a Restart

If the problem reappears every time you restart, the underlying NVRAM data may be corrupted. Try the following:

• Reset the System Management Controller (SMC) on Intel-based Macs. The steps vary by model, so check Apple's official documentation for your specific device.
• Run Apple Diagnostics by restarting and holding D on Intel Macs, or by following the Apple silicon startup options method above and selecting Diagnostics.
• Check for macOS updates via System Settings > General > Software Update.

Your Mac Won't Boot at All

If your Mac is stuck on a blank screen or won't progress past the Apple logo, the NVRAM reset alone may not be enough. Try booting into macOS Recovery:

1. Shut down your Mac.
2. Press the power button, then immediately hold Command + R on an Intel Mac, or hold the power button on an Apple silicon Mac until "Loading startup options" appears.
3. From the Recovery menu, run Disk Utility to repair your startup disk, then restart.

If the original issue persists after completing these steps, open a ticket with our support team and include the model of your Mac, the version of macOS you're running, and a description of what's happening. We'll be happy to investigate further.

Still Having Issues?