Stuck in Boot Loop on the Mac ?

Recently 2-3 friends have had this problem with their Macs. Maybe its a 3rd Party extension, or or add-on causing it, or maybe a hardware fault. Unfortunately, most of the time in India, if you take your Mac to your local Apple Third Party Reseller or Apple Authorized Service Provider, they will tell you that the only way to resolve this is to wipe your hard disk and by doing so you will lose all your data. But there are other ways….

First off, let me say, that the only Service Provider I’ve seen that doesn’t give up so fast on your data is PCSS, Mahim, Mumbai. I’ve had a fantastic journey with them, for over 15 years I think. I highly recommend going to them (rather than Maple or Chroma) for any Apple Related issues you may face.

Now back to the possible solutions/workarounds. One of the following list should pull you out of the Boot loop, and from there you can take measures to stop it from reoccurring. But first let’s look at what’s probably happening in the background.

Why is this happening ?

When you start up your Mac, the system generally shows a grey Apple Logo (the color changes depending on what OS you’re running) for a brief period followed by your Log In screen or directly jumps to your desktop (again depending on the settings you set in System Preferences).

However, in the in some cases, instead of booting properly, the system may display the Apple Logo and then reboot, repeating this step over and over again. This could be if there was a power outage/fluctuation, an app crashed, you ran out of HD space (yes, that’s happened to me, I download… a lot) or if your system libraries are corrupt.

Once the Kernel loads properly, even if there’s a problem with background services like location,  the computer will still boot, only in this case those particular background services may not work. This can be reset with a simple reboot. However, if your computer is not booting, but is stuck in a boot loop, then there could be two problems : it could be a kernel issue, or a hardware issue.

To narrow it down, lets take it one step further. During the boot, when the Apple Logo shows up, that means the System has a valid boot device (ie could be your bootcamp, or your HD, or your bootable HD). Then a spinning wheel shows up underneath. At this point, the system loads kernel extensions, boot caches and more. If one of these are causing a problem, your reboot should start immediately after the spinning wheel. If not, then it could be a add-on causing the problem.

How to circumvent this ? One of the following processes should get you out of this loop

Disconnect all Peripheral Devices

This technically shouldn’t come first, because it’s quite likely not to be the problem with the Mac. But I’ve had friends who gave their external Hard Disks to some PC users, which when returned caused some library plist or permission to malfunction. So we’ll eliminate this one right away.

  1. Shut down your computer by holding down the power key for a few seconds
  2. Disconnect all the external devices that did NOT come with your mac. This could be hard drives, USB hubs, FireWire Cables, etc
  3. Disconnect your Ethernet / LAN cables (if connected)
  4. Start your mac

If this works, then the problem is with one of the external devices. You can shortlist which one it is quickly by simple elimination. Once you know which one is causing the boot loop, you can get the device fixed by the manufacturer maybe.

Restart in Safe Mode

To restart in Safe Mode, hold down “Shift” while the computer restarts immediately AFTER you hear the start up Chime (not Before).

If the system loads properly, then you know that the issue is likely with some third party extension or add-on that you installed.  If you restart without the Shift key after this, and it goes back into the loop, you can be sure of it.

To fix this, in Safe Mode, run Disk Utility, and do the following :

Verify Disk Permissions –> Repair Disk Permissions –> Verify Disk –> Repair Disk

This should solve the problem. If not, try restoring to an earlier OS backup (assuming you use Time Machine, which you should)

Here’s a link to the Safe Mode on the Apple Support site (the link gives you an additional option of how to boot into Safe mode if (say) your Shift key on your keyboard isn’t working using Terminal during Start up.

Here’s an additional link that will tell you exactly what Safe Mode actually is and does for you 

Reset the PRAM / NVRAM

Your mac stores some settings in the PRAM or NVRAM (for newer Intel Macs). Even the selection of your start up disk is stored here. Sometimes, resetting the PRAM/NVRAM can help get you out of the reboot loop if its is one of these settings or kernel panic information causing the problem.

To do this, first Shut Down your Mac. If needed, hold the power key down for several seconds. It will force your mac to power down. Once this is done, do the following :

  1. Locate the “Command”, “Option”, “P”, and “R” keys on your Keyboard.
  2. Turn on your Computer, and before the Gray Screen appears, hold down Command-Option-P-R.
  3. Keep holding this down till you hear the start up chime 3 times.
  4. Release the keys.

If this gets you past the boot loop, your problem was possibly to do with the PRAM settings being corrupted. You may lose a few settings like Screen Resolution, or Start Up Disk selection if they were different from the default Mac ones (this hasn’t happened to me yet, so I can’t confirm that).

If this still doesn’t work, then read on.

Start from the OS X Install Disk – Use Disk Utility

  1. Insert your Installation Disk, or create a Bootable USB Drive and connect it to your Mac. Try to boot up in same version of the OS that you’re having the problem in if possible.
  2. Shut down the Mac
  3. Start up the Mac while holding down the “C” key
  4. Once started, goto Disk Utility in the Utility menu
  5. In Disk Utility, perform a disk repair of the Mac OS X volume. If no issues are found, do a permission repair as well.
  6. Try restarting without holding down the C key.

Start from OS X Install Disk – Archive & Install

If the Disk Utility doesn’t fix the problem above, but you’ve managed to start from the OS X Install Disk or the Bootable drive, do the following :

  1. Start up in the Install Disk by holding down the “C” key as described in the steps above.
  2. Goto the Install and Restore option
  3. Select your language. Click Continue. Read the license, click continue.
  4. Click the volume you wish to install to
  5. Click Options **do not miss this step, it’s important so that you do not lose your data
  6. Select Archive and Install
  7. Select the Volume where the Mac OS X was already installed
  8. Select Preserve Users and Network Settings (to keep a safe backup of your home directory, and any other users directories where your files may have been)
  9. Click OK
  10. Click Continue for the installation to begin

To check the list of files and folders that are stored before you continue to the last and final 2 options, please goto the following link and scroll down :: Mac OS X About the Archive and Install Feature

Erase & Restore – Time Machine as a Life Saver

Assuming that you have a backup of your entire OS and all the files and documents and settings, etc on Time Machine, this is a good option.

We know that your computer was working perfectly say 2-3 days ago ? Maybe more, maybe a week or a month ago ? Perfect ! Then do the following :

  1. Insert your Mac OS X Install Disk or Bootable Drive
  2. Shut Down you Mac
  3. Start up using the “C” key
  4. Do the same steps as in the previous “Archive and Install” process. However, when the choice is given, go for the “Erase & Restore” setting.
  5. Set up your mac as a new one. Reconnect your Time Machine disk
  6. Restore from a previous back up of Time Machine where you know for a fact it was working correctly (say a few weeks back)

If none of this works… :(

In the end, Apple does have a brilliant customer care. If not in India. If your computer is in warranty, you can ask for a new computer (since we’ve now shortlisted the problem to a hard ware issue). The Customer care should be able to replace the computer for brand new device if they cannot fix the problem. At this point, if you have Time Machine, you’re still home free, and can do a complete restore. If not, well you knew the risks of not backing up your data.

You can give your computer to the nearest Customer Care center. They will unfortunately return it to you without any of your data. If you have a second Mac that you use, you can use Migration Assistant to transfer the files over to this one so that atleast some of your documents or apps are saved.

If you’re warranty is about to run out, don’t fret. Here’s an article that will tell you how to extend that AppleCare plan you have for your Mac.

Finally….

The next time you see the following highly misleading, yet somehow wryly amusing comic strip on the internet (perhaps your friends shared it with you as mine did with me), redirect them to this page. There is 6 in 7 chance that if your computer crashes you will NOT lose your data. And don’t forget this is a Mac. There’s already a 95% chance that your computer won’t crash at all (I have one computer that hasn’t since 1994 OS 9.0).

Apple

And when all else fails, always remember, that while this comic above isn’t true, the ones below definitely are :

Windows

Linux

Well, almost true ;)

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