One of the most frequently mentioned Mac troubleshooting tips is resetting PRAM or NVRAM. But this doesn’t mean, however, that every time you notice an issue that the NVRAM needs to be reset. This advice usually comes from people who have no idea about the purpose of NVRAM, so we recommend taking a different approach rather than jumping on the first advice available. Using a speculative ‘let’s see if this helps’ method is not the right way of handling this situation, especially if the solution to a problem isn’t obvious. To correctly identify the right time to reset NVRAM, you should first understand what it does and why it needs to be reset.
What is NVRAM?
NVRAM stands for nonvolatile random-access memory, which your Mac uses to store settings such as: speaker volume; video and display information, including monitor depth, refresh rate, screen resolution, and number of colors; start-up disk selection; time zone; recent kernel panic information; keyboard repeat rate; RAM disks; disk caches and default system fonts. You can use the following Terminal command to view all NVRAM contents on your Mac:
nvram -xp
The information displayed in Terminal may well look like gibberish, but advanced users will find it useful if they know what they are looking for.
Older Macs store similar information in PRAM (Parameter RAM) instead of NVRAM, but the steps for resetting PRAM are exactly the same as resetting NVRAM. This is why NVRAM is usually mentioned alongside PRAM.
When to reset NVRAM/PRAM
While resetting NVRAM/PRAM is really easy, the only scenario where you need to proceed with resetting is when addressing an issue strongly related to any of the aforementioned contents of the parameter RAM. In other words, it’s only worth resetting NVRAM/PRAM if:
- You see a folder with a question mark instead of the Apple logo at startup;
- Your Mac starts up from a different disk to the one selected in Startup Disk preferences;
- You notice unusual issues on system boot;
- You notice an incorrect screen resolution;
- You notice issues with speaker sound or any issues related to the settings stored in NVRAM/PRAM.
Resetting NVRAM/PRAM is very easy; just follow the steps below:
After resetting NVRAM/PRAM you’ll need to open System Preferences and readjust the settings you have just reset such as display brightness and resolution, startup disk selection, speaker volume and time zone.
NVRAM reset for desktop Macs
Rather than relying on the power coming from the wall socket, desktop Mac computers contain an internal battery on their logic board to help retain NVRAM/PRAM settings when the computer is unplugged from the power source. This allows them to store settings such as sound volume and time zone, which would otherwise be reset every time you shut down or unplug your Mac. So this small battery – often called a PRAM battery – might need a replacement if you’re encountering issues related to these settings and the NVRAM/PRAM reset doesn’t help.
To address this issue, you will need to visit an Apple Store or Authorized Apple Service Provider to replace the battery.
István F.
Sander D.
