10.10.3 update hangs my iMac

Repair the Hard Drive and Permissions - Yosemite, Mavericks, Mountain Lion or Lion

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. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Repair

When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the 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. Select Restart from the Apple menu.

Now, download and install the OS X Yosemite 10.10.3 Combo Update.

Step 1

Take all the applicable steps in this support article. That's the starting point for any further efforts to solve the problem. Please read the whole article carefully and don't skip any of the steps, including the ones under the heading Additional troubleshooting. If you don't understand any of the steps, ask for guidance.

Also note that if you replaced the internal hard drive with an SSD, or if you're starting up from an external SSD, then that device may be causing the problem. Check the SSD manufacturer's website for a firmware update. The only solution may be to reinstall the original drive or avoid sleep altogether.

Step 2

If you're running OS X 10.8.5 or earlier, from the menu bar select

 ▹ System Preferences... ▹ Accessibility

If the checkbox at the bottom marked

Enable access for assistive devices

is checked, uncheck it and test.

If you're running OS X 10.9 or later, select

 ▹ System Preferences... ▹ Security & Privacy ▹ Privacy ▹ Accessibility

If any applications are listed on the right and have a checked box next to them, uncheck all the boxes and test. You may first have to click the padlock icon in the lower left corner of the window and authenticate as an administrator to unlock the settings.

Step 3

In the Energy Saver pane of System Preferences, uncheck the box marked

Put hard disks to sleep when possible

Step 4

If you don't already have a current backup, back up all data, then reinstall the OS.* You don't need to erase the startup volume, and you won't need the backup unless something goes wrong. If the system was upgraded from an older version of OS X, you may need the Apple ID and password you used.

If you installed the Java runtime distributed by Apple and still need it, you'll have to reinstall it. The same goes for Xcode. All other data will be preserved.

*The linked support article refers to OS X 10.10 ("Yosemite"), but the procedure is the same for OS X 10.7 ("Lion") and later.

Step 5

This and the next step must be taken as an administrator. If you have only one user account, you are the administrator.

Launch the Console application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

In the Console window, select

DIAGNOSTIC AND USAGE INFORMATION ▹ Diagnostic and Usage Messages

In the search box in the window's toolbar, enter "powerd" (without the quotes.)

You may see one or more lines like this:

com.apple.message.signature: Platform Failure

If you do see that, and you did everything in the preceeding steps, then you're dealing with an internal hardware fault. Make a "Genius" appointment at an Apple Store, or go to another authorized service provider.

Step 6

In the Console window, select

DIAGNOSTIC AND USAGE INFORMATION ▹ System Diagnostic Reports

(not Diagnostic and Usage Messages) from the log list on the left. If you don't see that heading, select

View ▹ Show Log List

from the menu bar.

There is a disclosure triangle to the left of the list item. If the triangle is pointing to the right, click it so that it points down.

You may see one or more reports with a name that begins with "Sleep Wake Failure" followed by a date. Select the most recent one. The contents of the report will appear on the right. Use copy and paste to post the entire contents—the text, not a screenshot.

I know the report is long, maybe several hundred lines. Please post all of it anyway.

It seems to be a bug with 10.10.3. I am having the same issue. Frustrating that there is not a fix at this point. I don't think it could be a hardware issue if it is happening to a ton of people all right after the new update.

The end result of the combo updater is the same, but the combo updater also replaces files from 10.10.1 and 10.10.2 which may have become corrupt. It will often fix other problems.