Reset the PRAM and NVRAM on a MacBook Pro have the same operations: 1. Shut down your Mac first. 2. Press the power button on MacBook Pro. 3. Before the gray screen, press the Command + Option + P + R keys simultaneously. 4. Hold those keys until your computer restarts and you hear the startup sound a second time. If your MacBook has a T2 chip, you should hold the keys until the Apple logo appears and disappears for the second time. 5. Release the keys and turn on the MacBook Pro.