i dropped my macbook and when i tried to turn it on it would turn on but the screen was black and i couldn't do nothing. so i thought it must be a hardware failure because i dropped it pretty hard. i tried resetting the NVRAM with these instructions:
Shut your Mac down. Press the Power key. Wait for your Mac to start loading. When you hear a startup sound, hold down Cmd + Option + P + R. Keep pressing the keys until you hear a second startup sound
and this fixed the laptop. it now works again.
How does dropping it cause damage to these NVRAM settings?