Resetting the Open Firmware / EFI Password on a Mac

These directions are only for Machines manufactured before 2011. Machines made after 2011 can only have the EFI Password Reset by an Apple Service Provider or at a Apple Retail Store.

While setting up a firmware password on a Mac provides a nice little extra bit of security, resetting the password is a fairly easy process as long as you have access to the internal hardware of the machine.

While this process was built in for those who forget there firmware passwords sadly it makes the firmware password essentially useless. The uselessness of the firmware password is furthered by Apples efforts to make RAM upgrades an easy at home process, by providing easy access to the RAM ports.

  1. Change the overall amount of RAM Installed in the machine. This is achieved by adding or remove a piece of RAM. The total amount of RAM must change but you must have at least some RAM installed in your machine in order for it to boot.
  2. Power on the mac and immediately press and hold command-option-P-R.
  3. The system will restart with the ‘bong noise’, allow it to do this 3 times. On the third ‘bong’ you can let go of the keys.
  4. The machine will now boot with a cleared password and reset PRAM/NVRAM.
  5. You can shut down the machine and replace the original ram configuration.
  6. The firmware password has now been removed.

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