Thursday, May 26, 2011

Resetting the System Management Controller (SMC) And Parameter Random Access Memory (PRAM) in MacBook Pro

Problem:
MacBook Pro does not charge its internal battery. Laptop works till it is connected to the main power supply. But as soon as we take out the power code laptop dies as no power is left in the battery.

Screens:
In the following screen you can see that the internal battery is not getting charged even though the unit is connected to the mains supply.


Platform:
Hardware: MacBook Pro 8,1 i7/4GB RAM /500GB HDD
Software:  Mac OS X 10.6.7

Reason:
Corrupted System Management Controller (SMC) and/or  Parameter Random Access Memory  (PRAM) is responsible for this.

Solution:
Reset System Management Controller to factory defaults. 
Note: Portable computers that have a battery you should not remove on your own include MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009).
  • Shut down the computer.
  • Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
  • On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
  • Release all the keys and the power button at the same time.
  • Press the power button to turn on the computer.  
Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

Reset PRAM and NVRAM
  • Shut down the computer.
  • Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously.
  • Turn on the computer.
  • Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
  • Hold the keys down until the computer restarts and you hear the startup sound for the second time.
  • Release the keys.
Apple knowledge base Links: