Apple Mac repair guide after crash

The Ultimate Mac Repair Quick Reference Guide

All in One Mac Computer Repair Guide!

More and more companies are buying Macs.  As a tech even if you aren’t a fan of the platform, knowing how to support them can give you an edge in the marketplace.  My IT consulting business landed several clients because of our ability to support Macs.  Sometimes the clients had almost all PCs and only a few Macs but because we knew both platforms, they would choose us over our competitors.  This is why adding Mac support to your portfolio can be a huge plus when trying to secure more clients or a new job.  So if you are interested in supporting Macs but are afraid to take the plunge, I have put together this quick reference guide just for you.


As a Mac computer repair Tech, you will find some or all of these tools will come in handy somewhere in your work.

Get Mac System Information

If in need of repair, you may want to quickly find your Apple Mac iOS. These are the first in this long list of Mac repair tools.

About This Mac

To quickly determine which version of OS X, processor, and how much RAM is installed, use About This Mac.

  1. Click on the Apple menu.
  2. Select About This Mac.

More Info:


System Profiler in Apple Macs

To find detailed information about the computer, use the System Profiler.

  1. Click on the Apple menu.
  2. Select About This Mac.
  3. Click the More Info button.
  4. Additional Step if the machine is running OS X 10.7 or later. Click the System Report button.

More Info:


Disk Related Issues and Repair Methods

I have written a number of articles relating to recovering data after hard disk drive problems occur. Two are: How to Recover Data from a Crashed Hard Drive (it is always one of my most popular posts with nearly 3000 shares and 1000 likes) and Put your Hard Drive in the Freezer to Recover Data (an awesome and surprising trick that really works!). Below are included disk tools for your or your clients’ Mac computer repair.

Repairing Disk Permissions

Incorrect disk permissions can cause startup problems, login problems, printing problems, and can prevent apps from launching.  If you are experiencing these problems, try repairing disk permissions.

  1. Launch Disk Utility which is located in Applications > Utilities
  2. Highlight the hard drive partition and click the “Repair Disk Permissions” button.

More Info:
See also:


Verify Disk & Repair Disk

If you suspect there is a problem with the hard drive volume or the hard drive itself try verify and repair disk.

  1. Launch Disk Utility which is located in Applications > Utilities
  2. Highlight the hard drive and click the “Verify Disk” button.  If the drive needs repaired, click the “Repair Disk” button.

More Info:


fsck Command – A very Handy Mac Repair Method for Disk Repair

If you cannot get into OS X at all either through normal boot or Safe Mode then use the fsck command in single-user mode to repair your disk.

  1. Shut down the computer.
  2. Turn the computer back on.
  3. Immediately press and hold the Command (⌘) key and “s” key to boot into single-user mode.
  4. At the command prompt, type: /sbin/fsck -fy
  5. Press return.

More Info:

Disk and Data Rescue

I’ve referred to these software programs in my article on How to Recover Data from A Crashed Hard Drive.


If Repair Disk cannot fix the problem then try DiskWarrior.  DiskWarrior works differently than most disk repair programs.  It attempts to build a replacement directory using data recovered from the original directory instead of trying to fix the existing directory.  This helps to prevent data corruption while attempting to repair your data.  The cost is $99.95.

More Info:


Data Rescue

If you need to recover data and DiskWarrior can’t do the job then try Data Rescue.  Data Rescue doesn’t attempt to repair the drive but instead focuses purely on recovering the data and copying it to a different drive.  The cost is $99.00.

More Info:


Drive Cloning

If the drive is going bad and you want to copy all the data to a new drive or you would just like to make a backup, you can easily create a bootable clone using SuperDuper or Carbon Copy Cloner.  SuperDuper is free but does not create the OS X Lion or Mountain Lion recovery partition on the new drive.  Carbon Copy Cloner does create the recovery partition but costs $39.95.

More Info:
See also:


Boot Related Issues

Resetting the NVRAM / PRAM

The NVRAM / PRAM stores basic hardware information, speaker volume information, screen resolution, start-up disk selection, and kernel panic information.  If you are experiencing issues with these try resetting it.

  1. Shut down the computer.
  2. Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
  3. Turn on the computer.
  4. Press and hold the Command-Option-P-R keys before the gray screen appears.
  5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
  6. Release the keys.

More Info:


Resetting the SMC

The SMC controls power flow and fan speed.  If you are experiencing issues with powering the machine on, sleep issues, unexpected power loss, battery performance issues, failure to recognize wireless card, bluetooth, or attached devices, try resetting the SMC.

Resetting the SMC on Mac portables with a battery you can remove

  1. Shut down the computer.
  2. Disconnect the MagSafe power adapter from the computer, if it’s connected.
  3. Remove the battery.
  4. Press and hold the power button for 5 seconds.
  5. Release the power button.
  6. Reconnect the battery and MagSafe power adapter.
  7. Press the power button to turn on the computer.

Resetting the SMC on portables with a battery you should not remove on your own

  1. Shut down the computer.
  2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
  3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
  4. Release all the keys and the power button at the same time.
  5. Press the power button to turn on the computer.  
    : The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve

  1. Shut down the computer.
  2. Unplug the computer’s power cord.
  3. Wait fifteen seconds.
  4. Attach the computer’s power cord.
  5. Wait five seconds, then press the power button to turn on the computer.

More Info:


Clean Caches and Other Items

If the system is sluggish try cleaning caches and other items.  The easiest way to do this is to use a program called Maintenance by Titanium Software

  1. Download Maintenance.
  2. Launch Maintenance.  It will want to verify the startup volume.
  3. Close out of all applications and click Continue.
  4. If you have already Repaired Permissions you can uncheck it.  Otherwise, click Execute.

More Info:


Booting into Safe Mode

If you are having trouble booting the computer into OS X, try booting into Safe Mode.

  1. Shut down the computer.
  2. Turn the computer back on.
  3. Press and hold the Shift key immediately.
  4. Continue holding down the Shift key until a gray Apple logo appears on the screen.  The computer will continue booting into safe mode.

More Info:


Creating a New User Account

Sometimes a user account can become corrupt preventing the computer from starting up and logging in.  If this happens, try creating a new user account in Safe Mode.

  1. Shut down the computer.
  2. Turn the computer back on.
  3. Press and hold the Shift key immediately.
  4. Continue holding down the Shift key until a gray Apple logo appears on the screen.  The computer will continue booting into safe mode.
  5. Choose Apple menu > System Preferences and click Accounts (or Users & Groups in OS X 10.7 and later).
  6. Click the lock icon to unlock it, and type an administrator name and password.
  7. Click the Add (+) button below the list of accounts.
  8. Choose a type of account from the New Account pop-up menu.
  9. Enter a name for the account.
  10. Enter the account password in the Password and Verify fields.
  11. Click Create Account.

More Info:


Booting from the Install Disc or Recovery Partition

If you need to reinstall the OS, restore from a Time Machine backup, or perform hard drive repairs using Disk Utility, boot the computer from the install disc or recovery partition.

OS X 10.6 or earlier (Install Disc)

  1. Insert the OS X install disc.
  2. Shut down the computer.
  3. Turn the computer back on.
  4. Immediately press and hold the Option key until you see the Startup Manager.
  5. Select the OS X install disc and press return.

OS X 10.7 or later (Recovery Partition – No Install Disc Required)

  1. Shut down the computer
  2. Turn the computer back on.
  3. Immediately press and hold the Command (⌘) and “R” key until the Apple icon appears.  The computer will then boot into the Recovery System.

More Info:


Hardware Related Issues

Apple Hardware Test

If you suspect that the computer may have a hardware issue, run the Apple Hardware Test.

  1. Shut down the computer.
  2. Turn the computer back on.
  3. Press and hold the D key before the gray startup screen appears.
    Note: Some Macintosh computers that shipped with OS X Lion and later support the use of Apple Hardware Test over the Internet. These computers will start up to an Internet-based version of AHT if the hard drive does not contain AHT.  An Internet-enabled connection via Ethernet or Wi-Fi is required to use this feature.
  4. If Apple Hardware Test does not start up you may need the install discs that came with the computer.
  • For Intel-based Apple computers that shipped with Mac OS X v10.5.4 or earlier, Apple Hardware Test is located on the Mac OS X Install Disc 1 and should be included with your computer.
  • For Apple computers that shipped with Mac OS X v10.5.5 to 10.6.7, Apple Hardware Test is located on the Applications Install Disc 2 and should be included with your computer.

More Info:


Hardware Warranty

If you discover a hardware problem, check to see if the Mac is still under warranty by visiting the Apple Service and Support Coverage page.  If it is, contact Apple Support to have the machine serviced.

More Info:
See also:


Hardware Repair Guides

If the Mac is out of warranty and/or you need to replace, upgrade, or repair the hardware, is the good resource for Mac repair guides.

More info:


54 Bit Driver Kit

In an attempt to prevent self-repair, Apple is using some nontraditional screws such as Torx screws and Pentalobe screws in their machines.  I recommend purchasing the 54 Bit Driver Kit from iFixit which contains all the bits that you will need when repairing a Mac.

More Info:


Application Related Issues

Force Quit an Application

If you have an unresponsive application, you can force it to quit using Force Quit.  This is similar to End Process in Windows when you use Ctrl Alt Delete.

  1. Press Command-Option-Esc (or click the Apple Menu and choose Force Quit).
  2. Choose the unresponsive application in the Force Quit window.
  3. Click Force Quit.

More Info:


Deleting Preference (.plist) Files

If you are experiencing issues opening an application or if the applications quits immediately after opening try deleting its .plist files.

  1. Open Finder and navigate to ~/Library/Preferences/ where ~ is the user home folder.  Note: If you are using a newer version of OS X then you will need to unhide the Library folder.
  2. Look for the application’s preferences file which is sometimes in the format “com..[product name].plist.
  3. Make sure you have Quit the application and then rename or delete the file.
  4. Relaunch the application which will also recreate the preference files.

More Info:


Uninstalling an Application

If deleting the preference files does not fix the problem, you may have to uninstall and reinstall the application.

  • See if the application has an uninstaller first.  If it does, run the uninstaller to properly remove the application.  Then, reinstall the application.
  • If the application does not have an uninstaller, you can uninstall it by dragging the application to the trash.  However, using a third party uninstaller will remove the application as well as other associated files.
  1. Download AppCleaner.
  2. Launch AppCleaner and drag and drop the application into AppCleaner’s window.
  3. Click Delete to remove the application.
  4. Reinstall the application.

More Info:


Miscellaneous Troubleshooting Steps

Unplug All Peripherals

Sometimes a connected peripherals can cause the system to have issues.  Unplug all peripherals that are not needed to see if that fixes the problem.


Software Update

Some bugs can be fixed by updating OS X with the latest patches.

  1. Click on the Apple menu.
  2. Select Software Update
  3. Install all necessary updates.  The system may need to restart when finished.


Restart the Computer

Just like a PC, sometimes a simple restart is all that’s needed to fix a Mac.

  1. Click on the Apple menu.
  2. Select Restart…

Summary of Our Mac Repair Guide With Reference Links

There are many Mac repair tools listed and explained above, and when you need one, you will know where to find them (right here on!). For those of you who have other Mac repair experience, please post any other repair tips in the comments section that you would like to add. For everyone else, I suggest you bookmark this page so you can access it quickly next time you have the opportunity to fix a Mac.


About The Author


Casey (Surname withheld for contractual and professional reasons) has contributed many great articles on He successfully started his own IT consultancy well over 10 years ago. While going through this tough yet rewarding experience he found there was a terrible lack of focused support out there for computer techs to start their own IT company. So he gravitated towards training and mentoring other computer technicians who want to create a part time or full time income as an IT consultant. He initially wrote courses to help computer technicians start their own IT consulting business (or side business). Many articles also help the general public save thousands of dollars in professional help by helping them DIY. He doesn't contribute directly to often any more due to leading a full family life and being Technical Director a at major US company (hence the requirement for privacy). However his contributions span over 10 years and some have been extremely popular (with so many comments we had to stop accepting more on some, and thousands of shares although it looks fewer after our change to https - we must get around to fixing that!). Having said this, we work to ensure his work is updated and continues to remain relevant.


  • trev

    Reply Reply February 26, 2013

    Sometimes bad hard drive can prevent a Mac from going past a white screen on startup and will prevent you from booting to something else, always try disconnecting the hard drive.

  • trev

    Reply Reply February 26, 2013

    If there was a liquid spill on a MacBook, try disconnecting the top case and use the power on pads to see of it will start

  • Karitz Bell

    Reply Reply November 18, 2014

    Not only repair, I used to repair, maintain and optimize Mac OS X with Stellar Drive Toolbox Utility. It is a combo pack of 14 tools to optimize Mac drive with in few clicks.

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