Mac Pro Cylinder won't boot up.

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Level 1

21 points

Mac Pro Cylinder won't boot up.

I purchased my Mac Pro Cylinder 10 months ago (new). It was working fine last night, then I turned it off (power completely off). When I turned it on this morning the power came on, it chimed, the Apple logo/progress bar appeared, but when the bar reached about half way, the computer shut itself off completely. I've tried opening it up and cleaning as much as I could (I'm leary about removing anything inside), reset the SMC, unplugged then started up again, and tried a different power cord. Nothing worked--it still shuts itself down halfway through startup. Is there something else I should try before taking it in to an Apple Store? Thanks for any advice.

Posted on Oct 25, 2017 12:07 PM

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Answer 1

CaptainS Author

Level 1

21 points

Oct 25, 2017 1:08 PM in response to Grant Bennet-Alder

Well, I managed to get to the Disk Utility and ran repair several times on both the hard drive (which it wouldn't do) and then on the OSX Base System, but that didn't seem to change anything. I ended up having to try reinstalling the OSX (Sierra), but it's telling me "This disk is locked" and won't let the reinstall continue. Of course, I can't get to any place that will let me "unlock" the disk. So, I'm stuck basically back where I started--the computer still won't boot to my normal desktop. Guess I'll have to go to an Apple Store and pay the piper. Thank you for your suggestions, though.

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Answer 2

CaptainS Author

Level 1

21 points

Oct 25, 2017 2:58 PM in response to Grant Bennet-Alder

Thank you very much for your advice--it's much appreciated. Will attempt to erase the drive.

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Answer 3

Oct 25, 2017 12:17 PM in response to CaptainS

That is a software issue that you may be able to fix yourself.

The solid Apple logo appears when the first Blob of software is loaded from a known location on the boot drive, and many things are initialized. To make further progress, many more files are needed, by name, so the File System is initialized and it attempts to Mount the boot drive for reading files. If the drive has a damaged directory, it cannot be mounted, so a disk utility repair is initiated. The progress bar continue across the screen for an unusually long time, and the disk repair progresses. when completed, an attempt at Mounting the drive is made again

-- if successful, boot-up proceeds as normal.

-- if not successful, the Mac is out of tricks and cannot proceed, so it powers off.

so the solution is to boot to Recovery, invoke Disk Utility, and run Disk Utility Repair several times until it comes clean or gets hopelessly stuck.

¿do you have a Trusted Backup?

¿do you have a spare external drive?

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Answer 4

Oct 25, 2017 1:45 PM in response to CaptainS

A disk that has an unrepairable directory will be, by definition, locked. The only way forward (PROVIDED you have a Trusted backup) is to erase that drive.

If you do not have a Trusted backup, you would need to use your "OS X Base System" or a new download to re-install MacOS onto an external drive, and run from that. Using additional Utilities such a Disk Drill or Prosoft Data Rescue, you can venture onto the damaged drive and try to salvage some files, if they are needed.

Only when you have either salvaged all you need or given up on salvaging anything more, you can try ERASing your internal boot drive, but all the files on it will be lost in the process.

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