Resetting SMC and NVRAM on macOS: Guide for Intel and Apple Silicon

Introduction / Why This Is Needed

The System Management Controller (SMC) and non-volatile random-access memory (NVRAM) are low-level components of your Mac. They manage power, fans, keyboard backlighting, system startup, and the storage of key settings. Over time, their state can become "corrupted" by invalid data, leading to various symptoms: the Mac won't turn on, won't wake from sleep, doesn't control screen brightness, can't see a Wi-Fi network, or boots into the wrong partition. Resetting the SMC and NVRAM is a safe, standard diagnostic procedure from Apple that often resolves these issues without needing a service center.

💡 Tip: Before performing any major procedure, especially if you're working on a MacBook, make sure it's connected to power.

Requirements / Preparation

1. Device: MacBook (any model), iMac, Mac mini, or Mac Studio.
2. macOS Version: These instructions are current for macOS Sonoma (14), Ventura (13), and Monterey (12). The procedures are virtually identical for older versions.
3. Architecture: It is critically important to know your processor type (Apple Silicon M1/M2/M3 or Intel). All subsequent steps depend on this.
4. Privileges: Resetting NVRAM on Intel machines via Terminal requires administrator rights (user password).
5. Backup (optional, but recommended): Although resetting NVRAM only deletes system settings (like startup disk selection, display settings), as a precaution, ensure you have an up-to-date Time Machine backup.

Step-by-Step Instructions

Step 1: Determine Your Processor Architecture (Intel or Apple Silicon)

Click the Apple menu () in the top-left corner and select "About This Mac". In the window that opens, find the "Processor" line.

• If you see "Apple M1", "Apple M2", "Apple M3", or similar — you have Apple Silicon.
• If it lists an "Intel Core i5/i7/i9" or another Intel processor — you have an Intel architecture.

Step 2: Reset for Mac with Apple Silicon (M1/M2/M3)

The procedure on Apple Silicon is significantly simplified compared to Intel.

Reset SMC (and NVRAM Simultaneously)

On Apple Silicon Macs, there is no separate command for the SMC. A full controller reset is performed via a reboot with held buttons.

1. Completely shut down your Mac: Apple menu → "Shut Down".
2. After it powers off completely, press and hold the power button (Touch ID/power button) on the keyboard for 10 seconds.
3. Release the button and wait a few seconds.
4. Turn on the Mac by pressing the power button.

Explicit NVRAM Reset (Optional, but Sometimes Necessary)

If the issue is specifically related to startup settings or display resolution, perform an explicit NVRAM reset:

1. Shut down the Mac (if it's on).
2. Turn on the Mac and immediately press and hold the key combination: Option (Alt) + Command (⌘) + P + R.
3. Hold these four keys for approximately 20 seconds. On an Apple Silicon Mac with a built-in display, you may hear a second startup chime (if enabled) or see the Apple logo appear and disappear twice.
4. Release the keys. The Mac will continue booting.

Step 3: Reset for Mac with Intel

Here there are nuances, especially for models with a T2 security chip (2018 and newer).

Reset SMC (System Management Controller)

For MacBook laptops (with T2):

1. Shut down the MacBook.
2. Press and hold from the left side the keys: Shift (⇧) + Control (⌃) + Option (⌥) and the power button simultaneously.
3. Hold all 4 buttons for 10 seconds.
4. Release all buttons and press the power button to turn on the Mac.

For desktop Macs (iMac, Mac mini, Mac Pro) without T2:

1. Shut down the Mac.
2. Unplug the power cable for 15 seconds.
3. Plug the power cable back in.
4. Wait 5 seconds and turn on the Mac.

For desktop Macs (iMac, Mac mini, Mac Pro) with T2: The procedure is identical to a T2-equipped laptop (see above).

Reset NVRAM (Non-Volatile Random-Access Memory)

1. Shut down the Mac (if it's on).
2. Turn on the Mac and immediately press and hold the key combination: Option (Alt) + Command (⌘) + P + R.
3. Hold these four keys for approximately 20 seconds. On an Intel Mac, you will hear a second startup chime (if not disabled) or see the Apple logo appear and disappear twice.
4. Release the keys. The Mac will continue normal booting.

⚠️ Important: If you have Windows installed via Boot Camp, an NVRAM reset may clear the startup disk selection. After booting into macOS, go to "System Settings" → "General" → "Startup Disk" (or hold the Option key at startup) to choose macOS or Windows again.

Step 4: Verify the Result

After a successful reboot, check if the original symptoms have disappeared:

• Have power issues (spontaneous wake, shutdown) been resolved?
• Is sound working again (internal speakers, headphones)?
• Has wireless connectivity (Wi-Fi, Bluetooth) been restored?
• Is an external monitor detected correctly?
• Is the Mac booting into the correct partition?

To verify an NVRAM reset on Intel, you can open "System Information" (via Spotlight or /Applications/Utilities/) and in the menu select "NVRAM". The boot-args parameter should be empty or contain only standard values.

Potential Issues

• Key combination didn't work: Ensure you press the keys immediately after the power button and hold them for exactly 20 seconds. On Apple Silicon, the duration may vary—use the second chime/logo as your guide.
• Problem not resolved: If after a correct reset (for both Intel and Apple Silicon) the main issue (e.g., Mac won't wake from sleep) persists, this may indicate a more serious hardware failure (battery, motherboard, memory). The next step is to run "Apple Diagnostics" (hold D at startup) or contact a service provider.
• Lost settings: After an NVRAM reset, you will need to re-select your startup disk (if you have multiple), reconfigure display resolution for external monitors, and possibly some settings in System Preferences (e.g., Dock position). This is normal.
• Mac won't turn on after SMC reset: On a MacBook with a severely depleted battery, the procedure may not work. Connect the MacBook to power and try again. If that doesn't help, the issue could be with the power adapter or battery.