You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Mac Pro a1186 shutsdown after booting halfway

I turn on my mac, and when the loading bar reaches halfway, it shuts off

Posted on Sep 5, 2023 12:02 PM

Reply
Question marked as Top-ranking reply

Posted on Sep 8, 2023 8:31 PM

@Grant's assessment of a failing drive is still the most likely suspect. You can try booting into Safe Mode to see if it may allow you to boot to the Desktop as it may bypass the damaged portion of the drive.


You can also try running the Apple Hardware Test (AHT) by booting Disc #2 from the original set of disks which shipped with your Mac from the factory (hold the "C" key down while rebooting/powering on the Mac with the disc in the optical drive). Unfortunately the diagnostics don't detect most drive failures, but if the diagnostic reports a problem (assuming all original Apple OEM hardware installed), then the failure is legitimate. If you don't have the original discs, then you can try creating a bootable AHT USB stick to check the hardware using the information in this article (the download links are all direct from Apple's own servers):

https://github.com/upekkha/AppleHardwareTest


It helps to try booting from external media to confirm the basic hardware is functional. Do you have an OS X 10.6 Snow Leopard upgrade DVD to test?

5 replies
Question marked as Top-ranking reply

Sep 8, 2023 8:31 PM in response to doves380

@Grant's assessment of a failing drive is still the most likely suspect. You can try booting into Safe Mode to see if it may allow you to boot to the Desktop as it may bypass the damaged portion of the drive.


You can also try running the Apple Hardware Test (AHT) by booting Disc #2 from the original set of disks which shipped with your Mac from the factory (hold the "C" key down while rebooting/powering on the Mac with the disc in the optical drive). Unfortunately the diagnostics don't detect most drive failures, but if the diagnostic reports a problem (assuming all original Apple OEM hardware installed), then the failure is legitimate. If you don't have the original discs, then you can try creating a bootable AHT USB stick to check the hardware using the information in this article (the download links are all direct from Apple's own servers):

https://github.com/upekkha/AppleHardwareTest


It helps to try booting from external media to confirm the basic hardware is functional. Do you have an OS X 10.6 Snow Leopard upgrade DVD to test?

Sep 9, 2023 9:40 AM in response to doves380

The initial "chime" sound is generated in software when your Mac passes the Power-On Self Test. If the chime occurs and/or startup continues, your Mac is working. The blank gray screen should light up. Then on to the disk Drive.


Accessing the Boot drive:

The solid Apple is not in the Mac's ROM at Cold start. The Apple logo can only appear when it is fetched in the first "blob" of software loaded from a 'magic' place on the boot drive, or re-run after a Restart. Then a whole lot of stuff is initialized, and the progress Bar moves part way across. After a cold start, seeing the solid Apple appear says your drive was able to produce the software that contains it.


If a prohibitory sign appears at this point, it indicates some fundamental part of MacOS is damaged or wrong version.

Mounting the Boot drive:

The next step requires a lot of files by name, so the File System is initialized, and the Boot Drive is Mounted. If the drive directory is damaged, the drive can not be Mounted, so your Mac begins one pass of Disk Utility Repair. This will take an additional about five minutes. During this process, the progress bar may be extended, and will grow by an additional amount not seen on a routine startup.

at the end of that process (which should not take more than about five minutes), it will attempt to Mount the drive again:

-- if the drive Mounts, boot-up continues.

-- if the drive cannot be Mounted, your Mac can do nothing more, so it powers off.

-- if the process stalls, this may indicate you have Bad Blocks on your Rotating Magnetic Boot drive (if so equipped). The re-reading of Bad blocks can take a very long time (on the order of a quarter minute for each Bad Block).

Mac Pro a1186 shutsdown after booting halfway

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.