Computer switches on then immediately turns off and endlessly...

[PraxxtorCruel]

Repeats this cycle until i hold the power button. It goes on for about 3 seconds then switches off. No signal from monitor but thats probably no surprise. When the computer was left for a couple of days and then switched on it remained on for about 10 secs and then switched off followed by the endless 3 seconds on then off unless i intervene.

What could this be? The last thing i did was transfer videos from cam to computer.

 

[Threepwood]

When it cycles off unplug the computer, while unplugged hold down the power switch for 10 seconds, then plug it back in and start her up.

Not gauranteed to work but it does sometimes.

 

[Vidar]

I'd also recommend clearing your cmos as this can often save a seemingly borked pc. You could maybe even try reseating the power connectors to the motherboard.