My Mac shuts down for no apparent reason

Question

I have my new mac mini running as a media center 24/7 at home. My problem is almost every day I come back home I find it off. It's in a locked room and the electricity is fine, so it must be from the mac itself.

Are there any logs that could give me useful information about why it shut down? any tips?

Appreciate your help

Answer 1

Logs are accessible via /Applications/Utilities/Console.app. I don't know what logs could be interesting though.

However, since you didn't mention it, what are your Energy Saver preferences in /System Preferences.app? Is the computer set to sleep or turn off (click the button Schedule... if nothing else seems in the dialog indicates something like this).

Regular Mac OS X shutdown are -- afaik -- cancelled by having unsaved changes in applications. Open Text Edit, write something, and leave it open. A message might pop up instead of the machine restarting:

But I'm not sure if this applies to all regular shutdown actions or only to user-initiated ones.

Answer 2

Another consideration could be either the power supply suddenly deciding to stop supplying power, or that the mini's fan has broken. It's easy to get temperature issues inside a case that small, and if the fan isn't moving, neither is the air.

I'd start with an SMU or PMU (I can't remember which the mini uses) reset, then verify that the minis fan is working by running 'yes > /dev/null' in the terminal (If you have a dual-core machine, start up a new terminal window per core) This will cause the CPU to heat up, which should also cause the fans to ramp up proportionally.

In general, you should strive to stimulate the failure, then troubleshoot the cause.

Answer 3

(since i can't post comments yet ) if it turns out to be a fan related thing, you could try SMCfancontrol, it is very useful in controlling temperature on the mac.