So I'm putting together my first gaming PC with the help of my friend via Skype. As far as I know, everything has been connected correctly however, I'm getting no visual feedback from the monitor and after about two minutes the system shuts down. The video card I'm using is an ATI Radeon HD 4850 (waiting on the 270X to be delivered). On the back of the card, a red LED flashes once every two-three seconds. All the case and cpu fans work. Again, I'm fairly new to building PC's so any help would be appreciated .