Does your Mac have problems related to the settings stored in the NVRAM ( the non-volatile random access memory that does not lose the information stored when power is cut off )? Or in the PRAM (which is a parameter RAM)? If yes, you may need to reset them, then. We explain how.
First you have to understand that the NVRAM is in a small amount of memory that your Mac uses to save certain settings and access them quickly. Similarly, the PRAM stores similar information. But in less quantity than the first. So the steps to restore these memories are the same.
The information that can be stored in the NVRAM includes the settings for the sound volume. Also, the resolution of the screen, the selection of the boot disk, the time zone and information about recent kernel or kernel failures. These settings depend on the Mac and the associated peripherals.
You can recognize if you have problems with NVRAM. If your Mac starts from a disk other than the one you selected in the boot disk options. Or if a question mark appears before starting. If this happens, you may have to reset this memory.
How to reset NVRAM?
First you must turn off your Mac. Turn it on again. And keep pressing these four keys at the same time: Option, Command, P and R for about 20 seconds until your Mac reboots. However, it should be considered that on Mac computers that have the T2 security chip of the apple brand, you can release the keys after the Apple logo appears and disappears a second time.
As a special note we recommend taking into account one thing. It’s that if your Mac uses a firmware password, the aforementioned key combination will do nothing. Or on the contrary it will make your Mac start from macOS recovery. To restore the NVRAM, we logically recommend first deactivating the firmware password.
When your Mac starts up completely, open the “System Preferences”. Check if the settings that have been reset are adjusted. Such as volume, screen resolution, boot disk options, among others.
If your Mac has problems with power, standby / wakeup functions. Or it has problems with the battery charge of the portable Mac or other aspects related to the power supply, Apple recommends reviewing the SMC (System Management Controller).