PC turns on-off-on

[Mixmaster5]

Hi there

 

I'm having a little problem with my PC:

 

When I press the power button it turns on for a second, then immediatly off, then after 2 seconds it tunrs on for good and also runs properly. Though it is a bit strange. Any ideas what causes the issue? It doen't happen when I reboot. Just when I turn it on.

 

Thanks. 

 

Cheers

[Jv2391]

I know this will sound weird, but are all your cables plugged into the right spots? Including the system panel cables (the small bunch that have similar attributes to pins in a way)?