Determine what is causing random restart

[ferrarr]

I ran the Apple Hardware Test (this is a Pre-2013 Mac). It found no issues.

Agree that it is a hardware fault. What I'm attempting to do is determine what that hardware fault is during a normal boot. Remember the machine runs fine in Safe Boot.

I have two memory sticks installed. I've removed each and tested individually. Neither cause the fault or show any errors during tests.

This isnt a keyboard, mouse or external hard drive issue. The issue happens even when all peripherals are disconnected and only in Normal boot mode.

What I need to find out is how I can progressively disable the startup of devices to determine what the hardware fault is.

Did you test each socket also? Try each stick, in each socket individually too?

 

[MacInWin]

Could it be the GPU? If it works in Safe Mode, but reboots in regular mode, is there a difference in the way the GPU is used in the two? I seem to remember reading that somewhere, but I don't know if it applies to the Mini.

 

[pm-r]

1. The issue first started in High Sierra

Any chance you have a bootable clone of a previous version you could try booting from.

Jake's suggestion of possible GPU problems makes me wonder if the HS is putting more load on the GPU, but that doesn't answer what extra(s) you have and why it runs fine in Safe Boot Mode???

Sorry, I guess I'm just babbling on here... and nothing really constructive offered.





- Patrick
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[MacInWin]

According to Apple:

Safe mode in OS X Leopard v10.5 or later also disables accelerated graphics. This makes the menu bar appear solid even if "Translucent Menu Bar" or "Reduce Transparency" is selected in System Preferences. Your screen might also "blink" or "tear" during login when your Mac is started in safe mode.

So my thinking was that the reboot is being triggered by the accelerated graphics of a normal boot. Longshot, but worth investigating. The rest of the article at Apple was a good read:

https://support.apple.com/en-us/HT201262

It mentions disabling some fonts. I wonder if the OP has any extra fonts installed?

 

[ferrarr]

It mentions disabling some fonts. I wonder if the OP has any extra fonts installed?

They did a clean/fresh install.

 

[MacInWin]

Just noticed this from post #17

Normal mode the fan speed being on full would cause it to restart sooner

Running the fan at full speed would be more of a burden on the power supply. So, maybe the power supply is right on the edge, but any time it sees a higher demand (added processing from all the loaded kexts in a normal boot, fans speeding up, higher GPU load in normal boot over Safe Boot, etc) it dies. (EDIT: or sags just enough to trigger a reboot) Then as soon as it dies, it comes back, the Mini reboots. It won't show the marginal condition if not tested under a load. Could be heat related inside the power supply. or just an overburdened marginal part.

 

[pm-r]

So my thinking was that the reboot is being triggered by the accelerated graphics of a normal boot. Longshot, but worth investigating.

I would think your logic makes very valid sense Jake. And doesn't HS tend to need and use more graphics horsepower than previous OS X versions???

I have no idea how one could test it all though.

Personally I'd try running an earlier OS X version than High Sierra. But I always keep a copy earlier working versions handy which makes doing so much easier.







- Patrick
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[galchin]

I've reinstalled back to El Capitan as this OS version didn't show the issue previously. Unfortunately the issue still takes place even on this version.

In relation to the GPU, is there any ability to reduce the work load on it (change settings etc)?

 

[pm-r]

I've reinstalled back to El Capitan as this OS version didn't show the issue previously. Unfortunately the issue still takes place even on this version.

Dang!! Well, it was worth a try.

Sorry, I can't help with any suggestions for reducing loads.





- Patrick
======

 

[MacInWin]

At this point about all I can think of is to take the Mini to the Genius bar at an Apple store and have them run their more detailed tests on it to see if they can find anything.

 

[chscag]

At this point about all I can think of is to take the Mini to the Genius bar at an Apple store and have them run their more detailed tests on it to see if they can find anything.

He's on his own with the Mini. A 2011 Mini is considered outdated by Apple and they will refuse to work on it. However, an authorized Apple reseller and service center might be willing but that will cost him for the diagnostics.

 

[MacInWin]

Won't they even run the diagnostics on it? I had thought they would do that, even if they won't repair it for him.

 

[chscag]

Won't they even run the diagnostics on it? I had thought they would do that, even if they won't repair it for him.

No, they won't even do that. Once an Apple device is vintage, you're on your own. I know.... it's a policy I don't agree with but I can understand why Apple stays away from old hardware.

 

[MacInWin]

Well, I guess he is on his own, then. SO what I would do is look for a way to stress the power supply in Safe Mode to see if he can force a restart. If he can, that would seem to point to the power supply. At that point, lacking proper testing, he could take a gamble and get a replacement power supply and follow iFixit to replace the one in there now.

I don't know what a PS would cost so I don't know if that is reasonable or not.

 

[galchin]

Thanks everyone for all the suggestions. Its a difficult one.

I decided to install Ubuntu onto it and see if that is able to reproduce the issue. First run worked with a minor issue with the graphics card which I was able to resolve. From there it ran without an issue. I'm now going to put on Maverics and see if I can reproduce the issue with that OS version in case its a driver that is stressing the hardware.

I'm not overly worried if I go either an older OS or a Linux distro. as this Mini will be used as a home server of sorts in the end.

 

[chscag]

Okay, sounds like a good plan. Keep us updated and good luck with it.

 

[Rocky97]

Based on what safe mode does:
"Verifies your startup disk and attempts to repair directory issues, if needed"
"Loads only required kernel extensions"
"Prevents startup items and login items from opening automatically"
"Disables user-installed fonts "
"Deletes font caches, kernel cache, and other system cache files"

https://support.apple.com/en-gb/HT201262

This is a safe operation. Maybe try delete the cache files on the mac as it's possible there's a cache/directory issue:
1. Open the mac terminal.
2. Type cd ~/Library/Caches in the command line to navigate to the cache folder.
3. Delete all cache folders by entering rm -R * .

Let me know if that helps!

 

[Randy B. Singer]

I was just doing some reading tonight, and something I read reminded me of this thread...

For the original poster....do you have third party anti-virus (AV) software installed on your Mac?

I just read that some folks have found that having AV software installed on their Macs can cause spontaneous restarts.

And, of interest, when you are booted in Safe Mode, most AV software is deactivated. So, your Mac won't be restarting itself while in Safe Mode if the culprit was your AV software!

 

[gsahli]

I think you should consider RAM a possibility. OS X uses a different "footprint" with Safe Mode. I suggest running memtest or the previously-mentioned hardware test for peace of mind.

 

[Randy B. Singer]

I think you should consider RAM a possibility.

See post #18 in this thread.