Hello!About a week ago i opened my pc to clean it with a tiny brush.I removed the graphic cards the cpu fan and the rams to be able to clean it,then i put them back on and when i pressed the power button the pc didn't boot.I removed the mouse-keyboard and monitor and i tried again but nothing happend.The fans is working,i have green light inside the pc but doesn't give me a beep.What i have to do to know what happend or to make it work again?