NVRAM (formerly PRAM) is a small piece of memory in your Mac that stores settings your Mac needs before macOS starts: which drive is the startup disk, the volume, the screen resolution, the time zone and information about recent errors. If that memory gets confused, your Mac can behave strangely. An NVRAM reset returns those settings to default. This article explains when that helps and how to do it.
Blue Apple repairs MacBooks in Amsterdam. An NVRAM reset is safe and quick, but it does not fix hardware problems; more about that at the end.
When does an NVRAM reset help?
- The Mac starts with a question mark or cannot find the startup disk.
- The sound keeps being at an odd volume or does not work.
- The screen resolution or brightness jumps back.
- The time or time zone is wrong after a restart.
- A brief error message you cannot place appears at startup.
On an Intel Mac
- Shut the Mac down.
- Turn it on and immediately hold Option + Command + P + R.
- Hold the keys for about twenty seconds. The Mac appears to restart.
- On Macs with a startup chime: release after the second chime. On Macs with the T2 chip: release after the Apple logo appears and disappears for the second time.
If it does not work, try another or the built-in keyboard. Some wireless keyboards are recognised too late at startup.
On a Mac with an Apple chip
On Macs with an Apple chip (M1 and newer, and the MacBook Neo) there is no key combination for an NVRAM reset. The Mac checks this memory itself at startup and resets it if something is wrong. Shut your Mac down, wait half a minute and start it again: that is the equivalent.
After the reset
- Check in System Settings, General, Startup Disk that the right drive is selected.
- Set the volume, resolution and time zone again if needed.
- Your files and apps stay; an NVRAM reset erases nothing.
Then restart the Mac once more normally. If the setting you chose is now kept, NVRAM was the cause. If it jumps back again, read on below.
NVRAM or SMC?
NVRAM is about settings such as startup disk, sound and screen. The SMC is about power, charging, battery and fans. If you have a charging or fan problem, read resetting the SMC on your MacBook. If in doubt you can try both; both are safe.
A question mark at startup
A flashing folder with a question mark means the Mac cannot find a startup disk. An NVRAM reset can help if the wrong drive was selected. If the question mark stays, the drive may be faulty or the system damaged. Read MacBook will not start up and Disk Utility and First Aid.
The problem comes back
If settings jump back after every restart, even after a reset, there may be something with the hardware, for example on very old Macs a flat coin battery on the logic board, or another logic board problem. Then a reset does not help permanently.
What we do at Blue Apple in Amsterdam
We test the storage and logic board when your Mac does not start properly or does not remember settings, and look at what can be restored, your data included. You hear beforehand what it costs. More on our page about MacBook repair in Amsterdam.
Frequently asked questions
What is the difference between PRAM and NVRAM?
PRAM is the old name. It works the same and the reset is the same.
Does an NVRAM reset erase my passwords?
No. Your passwords and files stay.
How do I know it worked?
You hear a second startup chime or see the Apple logo a second time. After that some settings are at default.
