Why does resetting NVRAM settings after i dropped my macbook fix it

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?

Reply to
landscapes
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Dropping it can cause (for instance) an acceleration sensor to retract disk heads and possibly shutdown power in an untidy way. Emergencies like power surges also can cause protective shutdowns. To ensure that emergency is past before resuming operation, it may set a bit in the PRAM to inhibit risky operations (like normal disk seeking, which does NOT happen with disk heads safely retracted).

There are many undocumented features that use PRAM (parameter RAM) NVRAM data to be written, that affect the startup functions (like identification of screen size and initialization requirements) and can inhibit the operating system from normal load and startup. The reset reverts all PRAM data to normal values, and does so before any initialization or loading of an operating system (so, it is outside of MacOS function, and has to happen during startup before MacOS takes over).

Reply to
whit3rd

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