auggie1929am

Q: imac el capitan problem

yesterday I uploaded el capitan on my imac 27" model. I turned on my imac this morning and heard the bell, saw the apple logo and a loading line below the aple logo. Loading did not begin. The computer seems stuck. I tried restarting computer, holding down Alt R during start up ... no difference. Help!

iMac (27-inch Mid 2010), iOS 9.0.2

Posted on Oct 3, 2015 10:48 AM

Close

Q: imac el capitan problem

  • All replies
  • Helpful answers

  • by Kappy,

    Kappy Kappy Oct 3, 2015 10:51 AM in response to auggie1929am
    Level 10 (270,288 points)
    Desktops
    Oct 3, 2015 10:51 AM in response to auggie1929am

    Reinstalling OS X Without Erasing the Drive

     

    Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears.

     

    Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.

     

    When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the indented Macintosh HD entry from the the left side list.  Click on the First Aid tab, then click on the Repair Disk button. If Disk Utility reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit Disk Utility and return to the main menu.

     

    Reinstall OS X: Select Reinstall OS X and click on the Continue button.

     

    Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless and more reliable.


  • by Linc Davis,

    Linc Davis Linc Davis Oct 3, 2015 11:32 AM in response to auggie1929am
    Level 10 (207,926 points)
    Applications
    Oct 3, 2015 11:32 AM in response to auggie1929am

    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.

  • by tostytexas,

    tostytexas tostytexas Oct 13, 2015 9:10 PM in response to Linc Davis
    Level 1 (4 points)
    iPhone
    Oct 13, 2015 9:10 PM in response to Linc Davis

    Mr. Davis

    Thanks for posting the info. It was the mouse and keyboard issue with my upgrade attempt. I used step 8 and after several power off and on attemps the system responded to the keyboard and mouse recognition and finally display came up to enter my password. Thanks again.

  • by voice_talent,

    voice_talent voice_talent Oct 14, 2015 8:29 AM in response to auggie1929am
    Level 1 (0 points)
    Oct 14, 2015 8:29 AM in response to auggie1929am

    I installed El Capitan on my iMac a few days ago. Now it doesn't recognize my printer, transcription foot pedal and just now, it says it has a problem backing up to my external HD. I am NOT very technically savvy. Should never have upgraded i guess. Any suggestions please?

  • by In-Line,

    In-Line In-Line Aug 22, 2016 2:19 PM in response to auggie1929am
    Level 1 (4 points)
    Desktops
    Aug 22, 2016 2:19 PM in response to auggie1929am

    Have the same problem , after El Capitan install can't boot up and if it does the screen has green vertical lines and then goes blank , I think it is a compatibility issue with the video card , but I don't get any answers.

  • by John Galt,

    John Galt John Galt Aug 22, 2016 3:34 PM in response to In-Line
    Level 8 (48,595 points)
    Mac OS X
    Aug 22, 2016 3:34 PM in response to In-Line

    In-Line wrote:

     

    ... I don't get any answers.

     

    You have not posted any questions. Please read Writing an effective Apple Support Communities question.