First let me thank you two for you answers.
Lyrius - will try.
Colgeek - They are firmly connected.
Btw another psu strange thing was more common.
Everytime I unplug the power (from the outlet) and then plug it on again my mouse lights up and i can't turn on the pc unless i do the above procedure that i described.
I was actually thinking that the problem could be something related to my motherboard abillity to charge usb devices without requiring the pc to be on.
Do you guys have any other ideas?