# Random powering off without a shutdown process

## skrapasor

I have an aluminum iMac and occasionally in Gentoo is just powers off as if the power was removed. It never does that in Mac OS X so I don't think it is a hardware or power supply problem. It could be overheating or something, maybe the kernel can't accurately detect the temperature. I don't think there are any logs when it happens because it just shuts off immediately with no time to write to a log. What kernel options should I have on to ensure that the kernel is functioning properly, or is it possible that the code just hasn't been written?

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## ONEEYEMAN

Hi,

Take a look at this.

Thank you.

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## skrapasor

That is for laptops, I have an iMac.

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## tgR10

 *skrapasor wrote:*   

> That is for laptops, I have an iMac.

 

acpi is a standard it ain't only for laptops

as wikipedia says

```
The Advanced Configuration and Power Interface (ACPI) specification is an open standard for unified operating system-centric device configuration and power management. ACPI, first released in December 1996, defines platform-independent interfaces for hardware discovery, configuration, power management and monitoring. 
```

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## skrapasor

"Please notice that this guide describes Power Management for laptops." Am I misinterpreting that?

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## energyman76b

computers don't just shut down. With acpi or without.

One question - is it always a shutdown or are there reboots too?

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## Total MAdMaN

 *skrapasor wrote:*   

> "Please notice that this guide describes Power Management for laptops." Am I misinterpreting that?

 

While the guide is showing you power management for laptops, that doesn't mean that the things in it are only for laptops, only that the setup shown is tailored to them. With a different configuration of the items in the guide you could have a setup for desktop or server machines.

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## energyman76b

yes, but you have to setup them first. Out of the box acpi does nothing but help managing pci devices and stuff.

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## skrapasor

Just for clarification, Wikipedia says:

 *Quote:*   

> To shutdown a computer is to turn its power off in a controlled way.

 

This is not what's happening. The computer doesn't go through any controlled shutdown process; it is as if the power cord is just unplugged and it turns off immediately. Anyway, to answer your question, it never reboots.

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## skrapasor

Is this what you guys really think is the solution, ACPI? If so, can you be more specific with what options would actually cause complete power failure? I never had to do anything like this on my two other gentoo desktops, and they have never powered off like this. Oh and by the way, I know ACPI is for all computers, but that guide specifically was for laptops.

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## pappy_mcfae

skrapasor,

If the case is closed, open it and see how clogged up the power supply/CPU fans are. If really clogged, clean them out with canned "air" and see if that helps. If the case is open, be sure that the fans are turning, and that the heat sinks to which they are attached aren't excessively hot. Warm is ok, hot isn't.

You're right, computers don't just die for no reason. Most usually, when a computer shifts from normal operation to self-shutdown or other such problems, there is a hardware fault somewhere; either overheating or a component/solder/connector failure. Cleaning out the dust can help if it's an overheating CPU, or power supply component. If it's any of the others, you may be looking at parts replacement.

Blessed be!

Pappy

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## energyman76b

yeah, pappy is right. Shutdown is either an emergency step taken by the mobo in an overheating event or failing hardware.

Sudden reboots are usually caused by bad PSU or bad ram causing triple faults.

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## skrapasor

Well then why has this never happened when it's running Mac OS X? It had been running OS X for over a year before I installed Gentoo, and it is still used quite frequently. That's why I don't think it is a hardware specific problem.

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## energyman76b

different software stresses the hardware differently? or maybe the hardware is failing right now  :Wink: 

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## pappy_mcfae

MacOS and Linux are not the same animal. If you can read your Linux partition from Mac, see if there is an error that gets put into /var/log/dmesg. If you can get to said file, post it after a failure. Without more info, it is a lot of guesswork.

Blessed be!

Pappy

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