Mystery shutdown

[Peppurr101]

Hello all,
Yesterday after a week long holiday, I came home and started my computer which ran fine until this afternoon.
I was out and about doing things and I left the computer on and logged online as I usually do.
When I came home, I found it had shut down and restarted and I was at my Windows Logon screen.
I figured we must have had some sort of electrical outage, so I logged in and let my Intel RAID storage manger do it's thing (it has to re-verify and re-match the data on my two RAID 1 drives)
I wandered back in a few minutes later to find the computer had gone into a CheckDisc. Check Disc didn't find any bad things so I let it run through and restarted, now all seems well again.

I am curious as to why it might have shut down in the first place and not quite sure where to look.
Control Panel>Administrative Tools>Event Viewer says no critical errors, just one error message that says the shut down was unexpected (duh).

Anywhere else I can under Event Viewer etc?
Thanks

PS.. I forget if my details are in here.. I am running Windows Home Premium SP 1 on a Dell XPS 420 System with 500G hard drives in RAID 1 and 4G of RAM

[DocWatson]

[quote name='Peppurr101' post='769081' date='03-Apr-2009 12:46'][/quote]

Sounds like your first instinct might have been correct. After any "unexpected" shutdown Windows will run Check Disk.

[DaveA]

A good power bump will do this, do you have a Power backup with batteries?

[Peppurr101]

[quote name='DaveA' post='769100' date='03-Apr-2009 20:28']A good power bump will do this, do you have a Power backup with batteries?[/quote]

Hi guys and thanks for your replies.
I think it did have something to do with the main power supply to the building. I don't have any clocks to flash when the power goes out, but my cable box had set itself to it's default 'how to set up' channel which usually happens with a power outage.
Can you tell me more about a power backup? Maybe recommend a type and cost?
Thanks
peppurr

[DocWatson]

Take a look here for a good overview of UPS (Uninterrupted Power Supply).

[wmfay1]

There are probably a large number of probabilities.
One class I can think of is simple hardware failure.
One thing which can happen is your 'Power Good' signal can momentarily drop.
There could be a bad component on your mother board, an unknown fault in the design of the mother board,
a bad power supply etc...
Or I even suspect software can cause some or most mother boards to cause Power Good to drop.
Without good (and expensive) equipment, it is very hard to determine this is happening with certainty.

This could be the next wave of deadly DoS attacks.
Have a piece of code execute some innocent looking instructions which cause Power Good on most computers to momentarily drop!
Then you get that code inserted to a common browser plug-in.
Everybody installs it. Doesn't have any "Viruses in it!"
Then on a predetermined rss feed that code gets executed bringing down lots of computers.
Maybe depending on the number of times that arbitrary code gets executed different machines go down.
But they are not fried! Nothing is wrong. No viruses. No malware.
Just an exploited internal flaw!

The computer I am currently using has done what you describe,
for well over three years now. The failure is un-reproducable; the worst kind.
The good news that most of the time Windows XP both SP2 and SP3
don't seem to mind and with NFS files check disk is not usually required.
I've seen it happen right in front of my eyes while typing like this.
I've done everything but swap mother boards.
No difference.
I also run Fedora on the same machine. It has never happened under fedora.
But that is no proof that it can't happen.
Moral:
Any operating system which you can't easily swap the mother board without a lot of hassle,
is worth NEGATIVE dollars.
btw-
halting on loss of Power Good is a safety feature!

[viking33]

[quote name='wmfay1' post='772200' date='24-Apr-2009 15:42']Moral:
Any operating system which you can't easily swap the mother board without a lot of hassle,
is worth NEGATIVE dollars.[/quote]

No offense meant here but you sound like the "prophet of doom" in your post.

Much more likely to have been a power outage or spike.
A good UPS probably would have prevented the problem but it sounds like after running chkdsk and a reboot it straightened itself out.

Unless I'm reading you wrong, your comment blaming the OS for not making it easy to swap the motherboard out is really wrong. How can a MB be swapped out "easily" if the OS was different? Changing a MB is no big deal but it's strictly a hardware function. The OS would have to recognize a different MB, no matter what.

[Peppurr101]

[quote name='viking33' post='772208' date='24-Apr-2009 21:56']No offense meant here but you sound like the "prophet of doom" in your post.

Much more likely to have been a power outage or spike.
A good UPS probably would have prevented the problem but it sounds like after running chkdsk and a reboot it straightened itself out.

Unless I'm reading you wrong, your comment blaming the OS for not making it easy to swap the motherboard out is really wrong. How can a MB be swapped out "easily" if the OS was different? Changing a MB is no big deal but it's strictly a hardware function. The OS would have to recognize a different MB, no matter what. [/quote]


Hello all,
Thanks for your help.
I am happy to report that it was a power outage that caused this problem.
I guess I just have to get used to the Intel Matrix Storage manager going through and re-verifying the data on my RAID mirror drives (RAID 0, RAID 1, whatever they are.. I can't keep 'em straight!)
It does this whenever there is an unexpected shutdown and though it takes about three hours, and I generally leave it alone to get on with whatever it's doing, it doesn't seem to affect the function of the computer at all. I can still surf and use all my programs.
Anyway, thanks again guys!

[macropod]

Hi Peppurr101,

With Vista, some Windows Updates force a re-start after a period of 5 minutes. A dialogue box warning of this pops up, and runs a countdown timer, but it's easy to miss if you're doing anything (the dialogue box doesn't stay on top) or, of course, if you're away from the PC.

There's been at least one such update recently. That's all the 'problem' may have been.