# Spontaneous hard shutdowns

## optiluca

Hi all.  My laptop has recently started spontaneously shutting down (with no warning whatsoever), in what I can only assume is some kind of hardware issue.  The pc will be happily idling, then it will immediately switch off, as if the power has been removed.  The only weird messages I have found in /var/log/messages are as follows:

```
Apr  1 15:09:00 localhost smartd[10962]: Device: /dev/sda [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 110 to 112

Apr  1 15:09:00 localhost smartd[10962]: Device: /dev/sdb [SAT], SMART Usage Attribute: 190 Airflow_Temperature_Cel changed from 72 to 67

Apr  1 15:09:00 localhost smartd[10962]: Device: /dev/sdb [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 28 to 33
```

However http://sourceforge.net/apps/trac/smartmontools/wiki/FAQ#Whyismydisktemperaturesreportedbysmartdas150Celsius suggests that this is normal.  Also, these messages do seem to occur independently of my shutdowns.

I have a feeling that this kind of behaviour has also occurred while running Windows, confirming the possibility of a hardware issue: it would just be nice to be able to pin it down in some way so that I can be sure that the machine gets fixed when I send it in for repair.  Does anybody know of any other useful logs that might help me work out what's going on?

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## ShadowCat8

Greetings,

Have you tried installing, configuring and running "sys-apps/lm_sensors"?

Usually when I have seen that behavior in the past, it tends to link back to the processor overheating.  Lm_sensors can tell you if that is the case.

HTH.  Let us know.

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## optiluca

I don't think anything is overheating, my desktop features this plasmoid so I should have noticed  :Very Happy:  http://i1311.photobucket.com/albums/s677/optiluca/Temps_zpsbf53786a.jpg.  I'll keep a closer eye on it anyway.

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## NeddySeagoon

optiluca,

```
/dev/sda [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 110 to 112 
```

If your HDD is operating at 110 Deg C, it won't last long.  The parts its made from are only rated for 80 deg C operation.

Your CPU is probably hotter than your HDD.

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## optiluca

 *NeddySeagoon wrote:*   

> optiluca,
> 
> ```
> /dev/sda [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 110 to 112 
> ```
> ...

 

The link from my OP explains that those values are not actually the temps in °C (despite the unhelpful names...)  Indeed, if I check temps with smartctl I get a much more sensible 36°C...

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## NeddySeagoon

optiluca,

Long shot but I've seen it on a few laptops with dying batteries.

What happens is that the battery goes short circuit for an instant, then heals.

However, for that instant, the power to the laptop is lost and it powers off.

These power offs are random.

To test, operate the laptop from AC but remove the battery, if the power offs stop, you need a new battery.

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