Does the SMC and PRAM/NVRAM get reset when you disconnect the battery in a macbook?

rodion15

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To reset the SMC on a mac desktop you need to disconnect the power cable for a few seconds then reconnect it.

I wonder if disconnecting the battery connector on the logic board resets the SMC or you need to use the Shift+Option+Command+Power-button key combination too.

I guess disconnecting the battery in macbooks resets the PRAM, as it drains the logic board it from power. Am I right?

Also: I heard that the best way to reset the SMC is to try the key combination with the battery disconnected, as was done in older macbooks. Not sure if this makes sense.
 

BadAsAl

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SMC can be reset by 1 of 2 methods. You can disconnect the battery and hold the power button for 5 seconds OR you can leave it shut off, plugged in to power, and use the key combination you mentioned. I prefer the disconnect battery method but that is only because most of the MacBooks I work on I already have them apart.

I do not think the PRAM gets reset by disconnecting the battery. Reason is, even after disconnecting the battery for days, when I boot the laptop again it still retains sound and brightness settings. These only get reverted to factory when I do the PRAM reset with the key combination.
 

rodion15

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When you say "You can disconnect the battery and hold the power button for 5 seconds", you mean with the magsafe disconnected? I never heard of this method, I'll try that. Thanks.


 

BadAsAl

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"When you say "You can disconnect the battery and hold the power button for 5 seconds", you mean with the magsafe disconnected? I never heard of this method, I'll try that. Thanks."

You have to actually disconnect the battery and the magsafe adapter before holding the power button down. This was easy on the MacBook's with the removable battery (2009 and prior) but it still works on the newer MacBook's with the "non-removable" batteries, it just requires taking the bottom off the MacBook to get to the connector for the battery. No big deal for someone who works on them, but for most people using method 2 is easier.
 
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