What Could Cause Random Shutdowns?

[Roodog]

My desktop PC has recently started shutting itself down, no indication, no reason I can think of. Would any of the system logs offer any insight? Which would I look at and what would I look for? I have Kubuntu 9.04 loaded and working well. I have searched these forums for any similar problems, but nothing matches.
David

[arochester]

Re: What Could Cause Random Shutdowns?

My first though is that it could be a hardware problem.

Check the little battery on your motherboard. If it is running right down this might cause problems...

[Qqmike]

Re: What Could Cause Random Shutdowns?

Usually, that's a sign of the power supply unit failing.
If you had a known-good P/S to trade into the box, that would probably tell you. Or a friendly PC shop that would test it for you without charging you the price of a new P/S.

Sometimes, the memory modules can cause such symptoms--failing memory and/or the memory is loose in its slots (=> re-seat the memory).

And, of course, it can be a heat issue (CPU, ICH. MCH) where the system is shut down for safety. (E.g., where the HSF unit comes loose from the CPU in a 775 board).

Or, a problem with the motherboard (faulty components/circuits/capacitors). I don't know anything about graphics cards, but they are known for causing quirky behavior, also, and you might re-seat it as well if you have a separate card (i.e., if you are not using embedded graphics).

The money is on the Power Supply, though, as a first guess.
There are P/S testers, but you have to get a good one, one that tests under load.

[Detonate]

Re: What Could Cause Random Shutdowns?

It can also be overheating. If the CPU reaches a certain temperature,, the computer shuts down. Check your CPU cooling fan and blow out all the dust and dirt from the heat sink.

[Roodog]

Re: What Could Cause Random Shutdowns?

Thanks for all suggestions - as a first step I'll strip the box down and clean and reassemble it. If problems persist I'll seek help at the place where I bought the machine. I have also noticed lots of repetitions of the following error msg "Unable to ennumerate USB device at Port 5" I am unable to do a console boot owing to this error being repeated endlessly. I have no new USB devices attached, only my printer.