Unexplained System Crash !

[Lou2000]

Anybody any idea what could have caused this ....

This is a general PC problem and in no way related to CM**. I'm not a PC professional, but I know my way around the inside of a PC

2.4ghz P4
256mb ram
WinXp Home
Gforce4 Ti 4200 (128mb)

System was running seemingly with out any problems.
Programs running:
CMAK (minimised)
Outlook express
PBEM Helper
Norton antivirus / Firewall
+ a few other smaller programs in systray.

Suddenly the screen went black and the PC sounded like it was goind a reboot. It didnt restart, could just hear the fans running and the screen remained black.

First thoughts were video card problems .. changed the card for a known good one (lower spec). No change. When removing the monitor cable the 'no signal' message was displayed on screen, so the monitor looks OK. Replaced the original graphics card

Tried with a bootable disk ... still no good.

Removed the heat sink & CPU .... everything looked OK, nothing seemed to be unusually hot.
No discolouration on any PCB's or strange smells. No unusual sounds and all the fans were running.

Replaced fan /heatsink /CPU and tried again ...

It all worked and here I am ... not sure for how long ?

I was starting to think it had overheated .. but not sure.

The only other thing is a couple of mins after it shutdown our street had a small (2-3 mins) power outage. Not totally unusual in this area.

I have a surge protector on the PC but not sure how good / effective it is.

PC has been back up now for 30 mins and seems stable.


Any suggestions appreciated ... assuming my PC stays up long enough for me to read them :rolleyes:

Lou2000

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(EDIT)
Lights in the house are dim and there is a team working on the mains supply in the street.
Note: The PC shutdown about 5 mins before the power cut. There was power to it when I tried all the restarts ... fans running etc.
Shutting down until they have finnished work :(

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[ December 14, 2003, 06:57 AM: Message edited by: Lou2000 ]

[junk2drive]

weird stuff lou
try PCmechanic (http://www.pcmech.com)

go to the forums and post your prob in general hardware. many helpful experts should have an answer esp with your specs included with your post

[Schrullenhaft]

If lights in your house are much dimmer than normal then it sounds like you have definite power problems in your area.

Most surge protectors are based on MOVs (Metal Oxide Varistors) that can age and become less effective with time. They work by shorting an over-voltage spike to the ground (not letting it pass through). Metal-oxide varistors do not last forever. If they are subjected to many surges over time, or perhaps one very large one, they can blow (sometimes this is obvious - burn marks - other time often it isn't). If this happens, your surge suppressor is no longer protecting your equipment from voltage problems. But how do you know when this happens? On older units (and most inexpensive ones currently made) you really don't know. On good units today though, an LED is provided that indicates if the MOVs are working or not.

A computer power supply has to supply several voltages at an appropriate level of current for the motherboard and other components to run. I don't know if a power supply would run if it didn't provide enough current to certain voltages because it wasn't getting enough current/voltage externally.

A CPU and video card can have high current requirements, so it could be possible that there was enough power for the other voltages, but the ones for the CPU weren't high enough to turn it on. That's just a guess though.

As for overheating... the Pentium 4 has the capability to continue running even when it exceeds its recommended die temp. The P4 just 'clocks down' its speed and continues to run (albeit quite slowly) - though there probably is a point where it would overheat and not run. I believe some P4s could even run without their heatsink (though the I'm not sure about the fastest ones - or if you're overclocking).

[Lou2000]

Thanks Schrullenhaft - sound advice (as always).

I'm faily convinced it was down to the local power problems as things seem to be back to normal now.

I'm going to invest in a new surge protector just to be on the safe side ...

... I'm sure you'll understand if I dont experiment with running my CPU without a heatsink. ;)

...Also thanks junk2drive for the link. I dont try the site, but I'll give it a browse at a later date.

Lou