|If it went dead--no fans or drives spinning and no LEDs--then it may be a power issue, as already mentioned. If it still seems to be powered on but with a blank screen then likely it's some internal hardware problem, maybe involving the screen or the connections to it. In that case there won't be a quick fix. It may be best to find a shop that has a 'free diagnosis' and see what they say. If it's still under warranty an approved repair shop should fix it without charge.|
If it's an older one (you are in the Vista forum) another option would be to find the same model on ebay, buy that one and then swap hard drives.