How to Reset NVRAM on a Mac

A small amount of your computer’s memory, called “non-volatile random-access memory” or NVRAM, stores certain settings in a location that OS X can access quickly.
The settings that are stored in NVRAM depend on the type of Mac you're using, and the types of devices connected to it. Information stored in NVRAM include speaker volume, screen resolution, startup disk selection and recent kernel panic information (if any). If you experience issues related to these features, you might need to reset the NVRAM on your computer.
To reset NVRAM follow these steps:

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