screen blackout

[fredrika]

When switching on PC twice recently, screen has been blacked out and there is nothing to do but switch off at wall socket. First time it successfully re-booted itself. Second time it switched PC off again. On retrying (never something I'm happy about) it re-booted again. Any advice on cause please before I take it to the for PC surgery. Could it be short of memory? I am using XP2 professional. Any answers would be appreciated and very welcome.

[ChuckFickens]

If it's a separate graphics card try removing the graphics card and refitting it just to re-make the connections.

[fredrika]

There is no separate graphics card! Thank you for answer.

[Aquariel]

Is it simply the screen that goes off (with computer still running), or the whole computer rebooting?

If it's rebooting, it could be something like a broken fan causing the CPU to overheat and shutting itself down.

It's always a good idea to regularly check the fans and clean out all the dust from them so they run properly.

Depending on your setup, it could also be that your system doesn't have enough cooling fans if, for example, you've installed a better graphics card or more hard drives, again causing overheating.