Reboot fail after installing El Capitan help!!

I have the same problem and have restored twice with the same problem. I did run across this solution, but am to tired to try it right now. I do not plan to shutdown again until I can get it fixed on my other mac computer. Having the same problem on both. Keep you posted.

https://forums.developer.apple.com/thread/21331

Either way, this is best fixed from Recovery Mode, but you shouldn't have to reinstall again to boot normally because moving the kexts in Recovery Mode should allow the boot process to continue as normal. Let me know how it goes.

1. So Boot into Recover Mode.
2. From the central menu open Disk Utility.
3. Then select the "Macintosh HD" partition, then the "Unlock" from the "File" menu (Skip this step if you can't see "unlock")
4. Select the Get Help Online link from the meunbar to open Safari.
5. Navigate back to this thread.
6. Select all of the writing in bold below and press cmd+C to copy it to the clipboard:

   cd "/Volumes/Macintosh HD/Library/Extensions/" ; mkdir Unsupported ; mv hp* Unsupported ; mv B* Unsupported ; cd "/Volumes/Macintosh HD/System/Library/Extensions/" ; mkdir Unsupported ; mv Elt* Unsupported ; mv ssud* Unsupported ; rm -Rf /Volumes/Macintosh\ HD/Library/Application\ Support/Rox* ; rm -Rf /Volumes/Macintosh\ HD/Library/Application\ Support/Check* ; rm -Rf /Volumes/Macintosh\ HD/Library/Filesystems/*fuse* ; rm -Rf /Volumes/Macintosh\ HD/var/folders/*

7. Then go to the Utilities menu, open Terminal and press cmd+V to paste the long command into it.
8. Restart normally a couple of times to confirm

Hey I ran across this fix and it worked for me on two machines.

Email this code to yourself, but change the machine name to YOUR EXACT machine name.

• cd "/Volumes/MacMini HD/Library/Extensions/" ; mkdir Unsupported ; mv Net* Unsupported ; mv Sym* Unsupported ; mv hp* Unsupported ; mv ndc* Unsupported ; cd "/Volumes/MacMini HD/System/Library/Extensions/" ; mkdir Unsupported ; mv Belc* Unsupported ; mv Eltima* Unsupported ; mv hp* Unsupported ; mv Hua* Unsupported ; mv Netg* Unsupported ; mv Remo* Unsupported ; mv RIM* Unsupported ; mv USBEx* Unsupported ; rm -Rf /Volumes/MacMini\ HD/Library/Filesystems/*fuse* ; rm -Rf /Volumes/MacMini\ HD/Library/Application\ Support/Sym* ; rm -Rf /Volumes/MacMini\ HD/var/folders/*

Boot in Restore mode.

Click OS help and Safari will open

Open your email and copy the code

Quit Safari and open Terminal from the top menu

Paste the code and hit return.

Give it a minute or two. When it is done you will then be able to quit Terminal.

Restart

Hi, I had the same problem, in my case it was a faulty kext of Eltima's SyncMate.

I removed it using terminal in the recovery partition.

You can check what is causing your problem (probably a kernel panic) keeping CMD+S pressed at the startup chime.

Your Mac will try to start in single user mode and will panic after a short time.

Examining what you will see on your screen you will hopefully find the software that is causing the problem.

Regards,

Luca

Hi everyone!

Think I've got the final solution, found a nifty trick at OWC's website.

The previous poster is almost right, but it is a tailored solution that will not work for everyone, because everyone has different Kext's by different developers and vendors.

It seems to be all about Kexts and they are in TWO locations, /Library/Extensions AND /System/Library/Extensions.

Try booting into the Recovery Drive. If you see a strange screen in recovery, you'll know it's hardware.

Boot into the Recovery Drive by holding down Command R when restarting.

When you log in you'll see something similar to this. A gray background with a box OS X Utilities.

Lost my text when I inserted the images. Oh well, bottom line is that booting with command R bypasses the login and goes to the smooth blue screen - after 2-3 minutes. Also, doesn't restart itself as it does with a normal login boot attempt. I was successful with command R a couple of times early on. I reinstalled El Capitan and even bought a new hard drive and tried to do a clean install to the new disk. That didn't work, but it may not have been the computer's fault.

Hope you can see the difference in the images. The top one is what I get now when I startup - blue horizontal lines but still legible. The 2nd is the smooth screen that I think everyone calls the blue screen of death. I can go to terminal using command S and to disk option with the option key, but right back to the blue lines when I choose the hard drive.

I've been looking at the new Macbooks. They're really tempting put I'm not giving up on this one just yet. With the I7 chip, this one still a better computer than what I can get for $500 in a windows machine.

Thanks again for your help.

Take each of these steps that you haven't already tried. Some of them may not be applicable to your model or your situation. Stop when the problem is resolved.

To restart an unresponsive computer, press and hold the power button for a few seconds until the power shuts off, then release, wait a few more seconds, and press it again briefly.

Step 1

The first step in dealing with a startup failure is to secure the data. If you want to preserve the contents of the startup drive, and you don't already have at least one current backup, you must try to back up now, before you do anything else. It may or may not be possible. If you don't care about the data that has changed since the last backup, you can skip this step.

There are several ways to back up a Mac that is unable to start. You need an external hard drive to hold the backup data.

a. Start up from the Recovery partition, or from a local Time Machine backup volume (option key at startup.) When the OS X Utilities screen appears, launch Disk Utility and follow the instructions in this support article, under “Instructions for backing up to an external hard disk via Disk Utility.” The article refers to starting up from a DVD, but the procedure in Recovery mode is the same. You don't need a DVD if you're running OS X 10.7 or later.

b. If Step 1a fails because of disk errors, and no other Mac is available, then you may be able to salvage some of your files by copying them in the Finder. If you already have an external drive with OS X installed, start up from it. Otherwise, if you have Internet access, follow the instructions on this page to prepare the external drive and install OS X on it. You'll use the Recovery installer, rather than downloading it from the App Store.

c. If you have access to a working Mac, and both it and the non-working Mac have FireWire or Thunderbolt ports, start the non-working Mac in target disk mode. Use the working Mac to copy the data to another drive. This technique won't work with USB, Ethernet, Wi-Fi, or Bluetooth.

d. If the internal drive of the non-working Mac is user-replaceable, remove it and mount it in an external enclosure or drive dock. Use another Mac to copy the data.

Step 2

If you've started from an external drive, make sure that the internal startup volume is selected in the Startup Disk pane of System Preferences.

Start up in safe mode. Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.

Safe mode is much slower to start and run than normal, and some things won’t work at all, including wireless networking on certain Macs.

The login screen appears even if you usually log in automatically. You must know the login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

If the startup progress bar gets stuck for more than a few minutes, or if the system shuts down automatically while the progress bar is displayed, the startup volume is corrupt and the drive is probably malfunctioning. In that case, go to Step 9. If you ever have another problem with the drive, replace it immediately.

If you can start and log in in safe mode, empty the Trash, and then open the Finder Info window on the startup volume ("Macintosh HD," unless you gave it a different name.) Check that you have at least 9 GB of available space, as shown in the window. If you don't, copy as many files as necessary to another volume (not another folder on the same volume) and delete the originals. Deletion isn't complete until you empty the Trash again. Do this until the available space is more than 9 GB. Then restart as usual (i.e., not in safe mode.)

If the startup process hangs again, the problem is likely caused by third-party software that you installed. Ask for further instructions.

Step 3

If the startup process stops at a plain gray screen with a movable cursor, then the login dialog may be active but not visible because of a bug. You might be able to log in by using the arrow keys or the cursor to select the password field and typing your password as usual.

Step 4

If Step 3 fails, the startup volume may be full. If you had previously seen warnings of low disk space, this is almost certainly the case. You might be able to start up in safe mode even though you can't start up normally. Otherwise, start up from an external drive, or else use the technique in Step 1b, 1c, or 1d to mount the internal drive and delete some files. According to Apple documentation, you need at least 9 GB of available space on the startup volume (as shown in the Finder Info window) for normal operation.

Step 5

If a desktop Mac (without a built-in keyboard) hangs at a plain gray screen with a movable cursor, the keyboard may not be recognized. Press and hold the button on the side of an Apple wireless keyboard to make it discoverable. If need be, replace or recharge the batteries. If you're using a USB keyboard connected to a hub, connect it to a built-in port.

Step 6

Sometimes a startup failure can be resolved by resetting the NVRAM.

Step 7

If there's a built-in optical drive, a disc may be stuck in it. Follow these instructions to eject it.

Step 8

Press and hold the power button until the power shuts off. Disconnect all wired peripherals except those needed to start up, and remove all aftermarket expansion cards. Use a different keyboard and/or mouse, if those devices are wired. If you can start up now, one of the devices you disconnected, or a combination of them, is causing the problem. Finding out which one is a process of elimination.

Step 9

Launch Disk Utility in Recovery mode (see Step 1.) Select the startup volume, then run Repair Disk. If any problems are found, repeat until clear. If Disk Utility reports that the volume can't be repaired, the drive has malfunctioned and should be replaced. You might choose to tolerate one such malfunction in the life of the drive. In that case, erase the volume and restore from a backup. If the same thing ever happens again, replace the drive immediately.

This is one of the rare situations in which you should also run Repair Permissions, ignoring the false warnings it may produce. Look for the line "Permissions repair complete" at the end of the output. Then restart as usual.

Step 10

If the startup device is an aftermarket SSD, it may need a firmware update and/or a forced "garbage collection." Instructions for doing this with a Crucial-branded SSD were posted here. Some of those instructions may apply to other brands of SSD, but you should check with the vendor's tech support.

Step 11

Reinstall the OS. If the Mac was upgraded from an older version of OS X, you’ll need the Apple ID and password you used to upgrade.

Step 12

Do as in Step 11, but this time erase the startup volume in Disk Utility before installing. The system should automatically restart into the Setup Assistant. Follow the prompts to transfer the data from a Time Machine or other backup.

Step 13

This step applies only to models that have a logic-board ("PRAM") battery: all Mac Pro's, MacBooks with a removable main battery, and some others (not current models.) A dead logic-board battery can cause a startup failure. Typically the failure will be preceded by loss of the settings for the startup disk and system clock. See the user manual for replacement instructions. You may have to take the machine to a service provider to have the battery replaced.

Step 14

If you get this far, you're probably dealing with a hardware fault. Make a "Genius" appointment at an Apple Store, or go to another authorized service provider.

This link will lead to the final solution to solve the problem: First Boot-Up Into El Capitan "Got Stuck"

If your Mac is randomly getting stuck during the boot process in Yosemite, it may be from unsigned extensions. This is most common with the Mac mini models.

First you will need to get it to boot before we can proceed.

Getting the Mac to boot:

1) Start the machine while holding down the Option-Apple-P-R keys

2) Wait until you hear the 3rd startup chime, then release the keys.

3) If that doesn't work try an SMC reset here: https://support.apple.com/en-us/HT201295

Now for the fix after you get the machine to boot:

1) Open Terminal in /Applications/Utilities

2) Enter "system_profiler SPExtensionsDataType > ~/Desktop/kextList.txt" without the quotes and hit return(this will take a while to run).

3) There should now be a kextList.txt file on your desktop, open it and press both the "Apple(Command)" and "F" keys to bring up the find.

4) In the find field insert "Obtained from: Not Signed" Copy the destination to the .kext file to a list for use later. (Click next to cycle through all of them.) Example: /System/Library/Extensions/JMicronATA.kext

5) Browse your drive to /System/Library/Extensions and remove any of the unsigned kext files.

6) Reboot and you should be all set.

Hello Fred from Doornspijk, to do a Recovery: Start up while holding Command and R simultaneously.

(described by Apple in this link: https://support.apple.com/en-us/HT201314)

After giving your credentials to the Apple app store It will download the installer, about 6Gb so it will take some time. After that, it will install and it will reboot your Mac. It will not erase your data nor do a clean install so everything should be fine and as it was.

Your Mac should at that point be working normal.

But: Do not restart again as it will be hanging again on the progress bar if you have faulty Kexts in /lLibrary/Extensions and/or /System/Library/Extensions.

The way to fix it I described in earlier postings, best to print the instructions first before you start looking for them. Also, note that Terminal commands are Case Sensitive.

Suspects are Etima (Syncmate), JMicronATA, old Parallel software and so.

You can, as I did, do everything also with Finder. If you do: Make sure that in the Finder preferences -> sidebar -> show Hard disks is marked and by advanced -> show all filename extensions is marked, so you can see the Kexts extensions and it is easier to find the /lLibrary/Extensions and /System/Library/Extensions mentioned earlier…

If you move Kexts to an other directory (e.g. Unsupported) make sure that you delete the Kexts from their original location. (It will ask for your password if you do.)

Good idea is to make a bootable USB stick with the ElCapitan installer. This will make future problems a lot simpler to solve.

Easy way to do it is using a great little free app you find at diskmakerx.com Note: it will look for the ElCapitan installer in your applications folder. If it is deleted (this happens almost always after installing) you must download ElCapitan again from the app store. Creating the USB stick does take a while, so go for a walk:-)

Hope this explained it a bit, let me know!

I Mis spoke Mavericks didnt kill my superdrive upgrading to Yosemite did. And I am not alone

imac won't play DVDs in Yosemite

WHich is why I am suspicisous. Another new OS and now this is where I am at

1. Somehow i was able to reboot and copy my files to external drive. All my files were there

2. Thought it was back to normal after 4 days of routine use

3. This morning while I was on a phone call, screen suddenly went black. I wasnt using any productivity software just reading a web page

4. Started interminable reboots

5. Cannot boot in safe mode

6. Command Recovery does not work

i am typing this on an old Lenovo laptop. It easily outlasted the 4 years of my $2000 Imac

Thanks for using Apple Support Community.

Prb

Mac Os x El Capitan will not start up after update.

Slt

1-Press and hold the power button for a few seconds until your computer turn off, then release the power button. Wait a few seconds and then press the power button to turn on your computer.

2-I previously wrote an article about how to fix Mac startup problems. Follow the tips in that article.

3-Try starting up in Safe Mode. To do this, turn on your Mac, when you hear the start up sound, press and hold the Shift key until you see the Apple logo. If your Mac can start up, the problem may be that your computer do not have enough space. Did you see any low disk space warnings before this problem? Your Mac should have at least 9 GB of free space. This article explains how to free up space on your Mac.

4-Reset NVRAM. To do that, turn off your Mac, then turn on, when you hear the start up sound, press and hold the Command-Option-P-R keys. Your computer will restart, when you hear the second startup sound release the keys.

5-Reset SMC.

6-Shut down your Mac. Remove all wired, external, non essential peripherals (such as scanners, printers etc), Then try turning on.

7-Repaid Disk. Shut down your Mac. Then turn on your Mac. Press and hold the Command (⌘) and R keys until you see a white screen with an Apple logo. Select Disk Utility then click Continue. Now select the startup volume (usually Macintosh HD) and click Repair Disk.

8-Reinstal OSX

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Jotted it down again: No offense, please try:

Getting yourMac to boot:

1) Start the machine while holding down the Option-Apple-P-R keys

2) Wait until you hear the 3rd startup chime, then release the keys.

3) If that doesn't work try an SMC reset here: https://support.apple.com/en-us/HT201295

Now for the fix after you get the machine to boot:

1) Open Terminal in /Applications/Utilities (-> make sure you are on your internal HD,... otherwise change it to your HD))

2) Enter "system_profiler SPExtensionsDataType > ~/Desktop/kextList.txt" without the quotes and hit return(this will take a while to run).

3) There should now be a kextList.txt file on your desktop, open it and press both the "Apple(Command)" and "F" keys to bring up the find.

4) In the find field insert "Obtained from: Not Signed" Copy the destination to the .kext file to a list for use later. (Click next to cycle through all of them.) Example: /System/Library/Extensions/JMicronATA.kext

5) Browse your drive to /System/Library/Extensions and remove any of the unsigned kext files.

6) Reboot and you should be all set.

This works Pedro.

Hey I ran across this fix and it worked for me on two machines.

Email this code to yourself, but change the machine name to YOUR EXACT machine name. The MacMini HD is the name of one of my macs. Make sure that you replace it with you exact hard drive name. Do not us HD if your hard drive does not have that in its name. Replace it everywhere in the text.

• cd "/Volumes/MacMini HD/Library/Extensions/" ; mkdir Unsupported ; mv Net* Unsupported ; mv Sym* Unsupported ; mv hp* Unsupported ; mv ndc* Unsupported ; cd "/Volumes/MacMini HD/System/Library/Extensions/" ; mkdir Unsupported ; mv Belc* Unsupported ; mv Eltima* Unsupported ; mv hp* Unsupported ; mv Hua* Unsupported ; mv Netg* Unsupported ; mv Remo* Unsupported ; mv RIM* Unsupported ; mv USBEx* Unsupported ; rm -Rf /Volumes/MacMini\ HD/Library/Filesystems/*fuse* ; rm -Rf /Volumes/MacMini\ HD/Library/Application\ Support/Sym* ; rm -Rf /Volumes/MacMini\ HD/var/folders/*

Boot in Restore mode.

Click OS help and Safari will open

Open your email in iCloud or where ever you access your email on the internet and copy the code

Quit Safari and open Terminal from the top drop down menus

Paste the code (command v) and hit return.

Give it a minute or two. When it is done you will then be able to quit Terminal.

Restart

Thank you GSfromNL,

This totally fixed my problem (on Mac mini from late 2014, 4G RAM).

I didn't actually remove all the unsigned kext files (heck there was even an unsigned Apple one) but just the ones which looked like they might well cause problems:

• Anything unsigned from Blackberry or RIM
• JMicronATA
• LivescribeSmartpen

Anything from HP or Samsung.

By the way, the other thing I did before all this was remove any unnecessary peripherals and remove Parallels from the Mac - thereby trying to keep it pute.

Cheers,

J