Troubleshooting a sudden shutdown

Question

Yesterday my computer suddenly powered down, without warning or going through the normal shutdown procedure.

I know it wasn't a powercut because everything else in the house stayed on. This is the first time it has happened, and it turned on again without a hitch (bar some fsck'ing).

My question is, where do I begin looking for a reason why. I appreciate it could be hardware, and was hoping someone could lead me in the direction of some logs, etc. that I could use to confirm that it isn't a problem in Ubuntu; or learn a little more about how it happened.

Thanks.

Solution

Sudden power down could possibly a protection mechanism against overheating. There should be kernel messages regarding this in your error logs at /var/log/kern.log and /var/log/debug

If it's related to overheating:

• What were you doing while the power got cut down? Something CPU / GPU intensive?
• Is your CPU overclocked?
• There are various applications to monitor your temperature, CLI and GUI. One program for the terminal is sensors (sudo apt-get install lm-sensors). KDE has a Temperature widget, I expect Gnome to have something similar for its panel.

Comments

[thomasmichaelwallace]

Hi, some good advice. Unfortunately in this case I know that it's not over-heating (having previously had trouble due to failing thermal couplant). Any other suggestions are more than welcome.

[Lekensteyn]

@thomas: try removing dust from the inside of your computer (desktop). I've once had random errors varying from an infinite loop in starting up to lock-ups which were gone after cleaning the inside. In the event of power-loss the logfiles are often corrupt or missing, anyway check your logs.

[thomasmichaelwallace]

thanks, i'll give that a go. haven't had any trouble since so guessing it was a bit of a dip in power or something.