The motherboard dident come with any monitoring utilities, but ill ckeck Dell's website just in case.

When the screen is black, theres nothing going on with the pc, nothing respond (mouse or keyboard). Its on a router with another pc and when the screen goes black the pc stops responding. The power light is on and the fans spin, and thats it.

On the monitor the power light starts flashing, it does that only when it dosent have a signal (it turns yellow in sleep mode).

Im not overclocking anything.

Whats a dry joint issue?

I already tried running it on a tv, the screen whent black after a few minutes.
Ive also tried removing the video card an only using the built in video adapter, same result.

Im starting to think that maybe i cliped or crushed a wire, , cause the case "folds open". And everything is pretty much a tight fit since its a its a mini-tower.
http://apcdigital.com/catalog/images/gx280MiniTower.jpg
Ill check all the wiring again tonight.