I like yourself am having the same problem. My monitor wont turn on as well. I replaced my original ASUS mobo with an ASUS M4A78-EM and a brand new CPU AMD Phenom Quad-Core processor 9850, as well as a brand new video card as well. The video card is an EVEA 9800 GTX +. I still get the same problem. The monitor and the keyboard wont come on. I have no clue as to why. I have replaced everything and still the same result as before. One thing that I have noticed is that the CPU fan is running really fast and really loud. All fans never shut off. Does anyone have a clue as to what the problem might be???? I need your help!!!!! I also have a new PSU as well. I have a LSP Ultra 650 watt.