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Henri00 Author

Level 1

4 points

Why is my tower restarting itself?

Dear support community:

Why is my Mac Pro restarting itself?

Dual Quad core 2.8 GHz, OSX 10.6.8, 10 Gigs of RAM

PCI card installed: Universal Audio UAD-2

It seems to exhibit these general behaviors:

It boots up successfully, acts perfectly fine for 8 minutes

and then restarts istelf.

Here is where the situation alternates a bit

1. It locks while rebooting, the power button light flashes slowly, the screen is black

2. It locks while rebooting, the screen shows a 'boot in progress' bar across the bottom

3. It reboots and is fine for the rest of the day.

4. Kernel panic screen while rebooting

If case 1 or 2 happen, I may have to interrupt and reboot one or two more times.

I have repaired permissions several times, booted from the OSX installer disk,

run disk utility and TechTool Pro a few times as well.

Please help!

best,

Henri

Mac Pro, Mac OS X (10.6.8), Dual Quad core 2.8 GHz, OSX 10.6.8

Posted on Feb 27, 2012 11:25 AM

Best reply

Grant Bennet-Alder

Level 10

127,567 points

Posted on Feb 27, 2012 11:40 AM

shows a 'boot in progress' bar

That is doing a "Repair Disk" -- NOT Repair permissions -- repair permissions is for a fairly obscure problem of Applications not starting

Kernel panic screen while rebooting

If you have kernel panics, post the log here and readers can help you decode it.

Mac OS X: How to log a kernel panic

And one more thing...

check to be sure the AC power cord is tight.

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19 replies

Henri00 Author

Level 1

4 points

Mar 2, 2012 1:31 PM in response to Grant Bennet-Alder

Should I update to Lion? Will this make any difference?

Linc Davis

Level 10

209,547 points

Mar 2, 2012 5:16 PM in response to Henri00

Will this make any difference?

I'd expect it to make things worse. That's what usually happens when you upgrade a misconfigured system. If you won't even test with the third-party drivers removed, I don't have anything else to suggest.

Henri00 Author

Level 1

4 points

Mar 2, 2012 5:45 PM in response to Linc Davis

Grant - yep, I've cut them all, or updated others just in case. We'll see what that gives in the morning.

Linc - I'm sure you're right...I'll wait until this is squared away before updating.

thanks again, have a great weekend

May 19, 2014 1:31 PM in response to Henri00

The same thing is happening to my Mac pro tower (late 2009 running Snow Leopard).

I have done some reading of people with the same problem. Some say it has to do with the way the snow leopard allocates the memmory, and recommend doing a permissions repair, showing it reduces the active memory usage in Activity Monitor.

Link Davis recommended using the terminal to inset a command to find out more:

and to see if a message appears in a separate window after it has run.

In my case it did:

Fri May 16 21:12:25 Joes-Pro kernel[0] <Debug>: 00000000 ffffffff Intel82574L::timeoutHandler - link is down

Fri May 16 21:12:36 Joes-Pro kernel[0] <Debug>: Previous Shutdown Cause: -128

he said a negative number could indicate some kind of hardware failure (very vague)

I have tried all these things including starting up from a different internal drive, starting in safe mode, holding down the option key and starting from another drive, and the restarting problem has occurred during it all. Finally after pushing in my power button and forcing a shutdown and then zapping the PRamwhen it started back up stabilzed it temporarily.

I've had the machine at an Apple certified repair and diagnostic place and they couldn't find anything.

They suggested replacing the drive(s), but I have done extensive low-level scans and no bad boot blocks have been found. The hard drives pass the tests in Disk Utility

Why is my tower restarting itself?