TS1411: Your Mac won't start up in Mac OS X (Mac OS X 10.3.9 or earlier)

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leavesliketeeth

Q: what are the keys to hit when starting up a mac to clean a drive, it's apple command, and two letter keys. what are they though?

My computer won't go to the log in screen an I am hoping this helps, thanks!

Posted on Jan 12, 2014 6:58 PM

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Q: what are the keys to hit when starting up a mac to clean a drive, it's apple command, and two letter keys. what are they though?

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  • by Klaus1,

    Klaus1 Klaus1 Jan 13, 2014 1:22 AM in response to leavesliketeeth
    Level 8 (48,858 points)
    Jan 13, 2014 1:22 AM in response to leavesliketeeth

    What Mac do you have, with what version of OS X?

  • by a brody,

    a brody a brody Jan 15, 2014 5:12 AM in response to leavesliketeeth
    Level 9 (66,876 points)
    Classic Mac OS
    Jan 15, 2014 5:12 AM in response to leavesliketeeth

    command-option-p-r zaps the Parameter RAM, but does not empty the drive.  It does reset a lot of hardware to factory settings if the computer is under 4 years old.  Older than 4 years old, there is a battery on some machines, while there is a capacitor on the logicboard of others that manages the PRAM.   That's why it is so important to know your Mac model. 

     

    command-option-o-f brings up the open firmware, which is helpful in finding out what version of firmware you have, and manually resetting the NVRAM of some machines.

     

    command-R will restore newer than July 20, 2011 operating systems through an online download if the machine has the correct firmware already applied.

     

    http://support.apple.com/kb/HT4904 discusses that firmware.  Newer Macs based on the release date of the Mac model in question will already have that firmware applied.

     

    When you say a "clean drive", you do mean totally removing the data?   Cause if you do, that's a function of Disk Utility, which will come up in the command-R boot on machines that support it.  Otherwise, you need an installer disc supported by the Mac in question, which will have Disk Utility.

     

    Older Macs than Mac OS X use the utility Drive Setup to erase.

     

    Option key lets you boot most Macs from installer CD, if supported.

     

    Macs generally will not support an older operating system than they shipped with, or an installer disc from a Mac of a different age or model.