Key combinations to troubleshoot your Intel-based Mac at start-up

Many articles you read on Mac troubleshooting mention troubleshooting methods like resetting the NVRAM, starting in FireWire Target Disk Mode, starting in Safe Mode, or starting in Single-User Mode, but fail to explain exactly how to do that.

Many articles you read about Mac troubleshooting mention troubleshooting methods such as resetting the NVRAM, starting in FireWire Target Disk Mode, starting in Safe Mode, or starting in Single-User Mode, but fail to explain exactly how to do that. This article breaks it down for you.

Apple has released a knowledge base article describing the key commands and what they enable when pressed during start-up:

  • Press C during start-up: Start from a bootable CD/DVD, such as the Mac OS X Install disc.
  • Press D during start-up: Start the Apple Hardware Test when the Install DVD 1 is inserted in your Mac's drive.
  • Press and hold (Command + Option + P + R) until you hear two beeps: Reset the NVRAM.
  • Press Option during start-up: Loads Startup Manager, enabling users to select which volume they would like to boot from. Pressing N will show the first bootable Network volume as well.
  • Press the Eject button, press F12, or click and hold the mouse or trackpad button: Ejects any removable media.
  • Press N during start-up: Attempt to start from a compatible network server (NetBoot).
  • Press T during start-up: When two Macs are connected via FireWire, this will start one in FireWire Target Disk Mode (two Macs with FireWire ports are required).
  • Press Shift during start-up: Starts your Mac in Safe Mode, temporarily disabling log-in items.
  • Press (Command + V) during start-up: Starts in Verbose Mode.
  • Press (Command + S) during start-up: Starts in Single-User Mode.
  • Press (Option + N) during start-up: Start from NetBoot server using the default boot image.
Apple recommends pressing the start-up key combinations immediately after hearing the start-up tone.


Be sure to check us out on Twitter and the CNET Mac forums.
Do you have questions, issues, or stories you would like to see on MacFixIt? Email Us.

About the author

    Joe is a seasoned Mac veteran with years of experience on the platform. He reports on Macs, iPods, iPhones and anything else Apple sells. He even has worked in Apple retail stores. He's also a creative professional who knows how to use a Mac to get the job done.

     

    Join the discussion

    Conversation powered by Livefyre

    Don't Miss
    Hot Products
    Trending on CNET

    HOT ON CNET

    Get ready for iOS 8

    Here's what you need to know before downloading iOS 8 on your iPhone or iPad.