Sleep Wake Failure, nearly 100%

Hi jroza1,

Thanks for using Apple Support Communities. Based on what you stated, it sounds like you are getting a kernel panic. I would recommend that you read this article, it may be able to help the issue.

OS X: When your computer spontaneously restarts or displays "Your computer restarted because of a problem." - Apple Support

Hardware troubleshooting

Disconnect the external drive used in the above test to determine if the kernel panic is due to a hardware issue.

Check peripheral devices first

Go to the next section if you have no devices attached to your Mac.

1. Turn off your Mac.
2. Disconnect all peripheral devices. If you have a desktop Mac, make sure all you have connected is a display and Apple keyboard with Apple mouse or trackpad.
3. Turn on your Mac.
4. Use your Mac for the amount of time it would usually take for a kernel panic to occur.
5. If a kernel panic does occur: Proceed the next section to check the internal RAM and third-party hardware.
   If a kernel panic does not occur: Power down the Mac and connect one peripheral device at a time and test until a kernel panic occurs.

   Note: A combination of peripherals may be the cause of a kernel panic. Disconnect one peripheral at a time to see if it causes a kernel panic by itself. If the kernel panic does not occur, continue to add peripherals until you find the other peripheral needed to cause the kernel panic.

Check internal RAM and third-party hardware

1. Turn off your Mac.
2. Reseat the Apple RAM, and remove third-party RAM and third-party internal hardware. If you do not have the Apple RAM that came with the system, reseat the third-party RAM.
3. Turn on your Mac.
4. Use your Mac for the amount of time it would usually take for a kernel panic to occur.
5. If the kernel panic does not occur: The third-party RAM or internal third-party hardware may need to be replaced.
   If a kernel panic does occur: Bring your Mac to an Apple Store, or an Apple Authorized Service Provider for service and support. Be sure to ask that, if the drive needs reformatting or replacing, they contact you about escalating your case to a special data recovery service. If you plan to visit an Apple Retail store, you can make a reservation (available in some countries only).

Software troubleshooting

Disconnect the external drive used in the above test to determine the kernel panic is due to a software based issue.

1. Start the Mac from OS X Recovery and reinstall OS X on your Mac.
2. Start from the installation of OS X you just created.
3. Use Software Update to install all updates until it reports "Your software is up to date."
4. Download and install any third-party software updates before reinstalling third-party software, especially drivers and kernel extensions.
   Examples include:
   • Virtualization software
   • Drivers for add-on third party display cards
   • Anti-virus software
   • Networking software (especially software which enables third party network devices)
   • Add-on file system support software; for example, software that lets your write to NTFS formatted media.

If the issue continues, you will need to erase and install OS X as follows:

1. Start the Mac from OS X Recovery.
2. Complete a disk image backup via Disk Utility of the internal drive to an external drive with enough free space.
3. Erase the internal drive using Disk Utility.
4. Install OS X.
5. Start from the internal drive.
6. Use Software Update to install all updates until it reports "Your software is up to date."
7. Re-install your third-party apps and copy your user data from the disk image backup you created in step 2.
   Note: Avoid copying data from the /Library and /System folders on your backup disk image.

Take care

All Macs on your network must run the latest public release of Yosemite. After that, reboot all devices on the Network. Routers, Apple TV, Modem...everything. The poison pill is "discoveryd". See this link from Macrumors:

http://www.macrumors.com/2015/05/26/apple-discoveryd-replaced-with-mdnsresponder /

That will fix it. 🙂 That is until someone logs on to your network with Yosemite running "discoveryd" instead of the reliable "mdnsresponder". If that happens another full reboot of the entire network system resolves it.