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You may also try SMC and NVRAM on your Mac. Follow the instructions <a href="http://www.macworld.com/article/2881177/how-to-reset-your-macs-nvram-pram-and-smc.html" rel="ugc">here</a>. <br />
<br />
In addition to that, you might want to press SHIFT while booting up and see if you can go into the OS.
</div>


You may also try SMC and NVRAM on your Mac. Follow the instructions here [http://www.macworld.com/article/2881177/how-to-reset-your-macs-nvram-pram-and-smc.html].

In addition to that, you might want to press SHIFT while booting up and see if you can go into the OS.

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I was able to reformat the HD and install the OS from the recovery partition.
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I was able to reformat the HD and install the OS from the recovery partition.

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<div class="content wysiwyg-content">
Hello,<br />
<br />
I have a client that brought in a Macpro All-In-One. When the power button is pressed the booting chime sounds, followed by the grey screen with the apple logo. Shortly afterward, the progress bar appears at the bottom (empty). Then the progress bar disappears, without any progression on it, and a circle loading icon appears. About fifteen seconds after the loading icon appears the Mac turns off completely. I can depress the power button again and repeat this cycle multiple times with no alteration in pattern or timing.<br />
<br />
Any thoughts or ideas would be greatly appreciated.<br />
<br />
Thank you,<br />
Chris
</div>
</div>


Hello,

I have a client that brought in a Macpro All-In-One. When the power button is pressed the booting chime sounds, followed by the grey screen with the apple logo. Shortly afterward, the progress bar appears at the bottom (empty). Then the progress bar disappears, without any progression on it, and a circle loading icon appears. About fifteen seconds after the loading icon appears the Mac turns off completely. I can depress the power button again and repeat this cycle multiple times with no alteration in pattern or timing.

Any thoughts or ideas would be greatly appreciated.

Thank you,
Chris

Mac All-In-One doesn't finish booting

Mac OS X is the desktop operating system from Apple Inc., found on Macintosh computers. OS X consists of a Mach/BSD-based kernel, operating system interfaces primarily based on FreeBSD and additional frameworks (written in C, C++ and Objective-C providing user interface and application-level services.

Mac OS X

All of Apple's hardware is produced solely by Apple Inc., who determines internal systems, designs, and prices. Apple buys certain components wholesale from third-party manufacturers. The current Mac product family uses Intel x86-64 processors. All Mac models ship with at least 1 GB RAM as standard. Current Mac computers use ATI Radeon or nVidia GeForce graphics cards and include a dual-function DVD and CD burner, called the SuperDrive. Current Apple hardware includes the iPad, iPhone, iMac, Mac Pro, Macbook, iPod and Apple TV. Discontinued hardware includes the Apple I, Apple II, and the Apple III, the Lisa, the Newton, the Quadra, Performa, Centris, Macintosh II and LC series, the Power Macintosh, iBooks and the MacBook.

Apple Hardware

Apple's early computers ran on a variety of operating systems, including a Pascal version and one based on CP/M, before releasing its ProDOS with the advent of its 16-bit computer. With the release of the Lisa, which had its own OS, Apple and computing entered the graphical age; it was followed by the Macintosh, which offered a series of "System" operating systems. Other Mac operating systems included PowerPC until Apple acquired NeXT and folded it into the Mac OS. Current operating systems for Apple devices are Mac OS-X and iOS.