have you tried it on another pc to see if the monitor is fine?? on monitors if the main power board goes or the backlight fails it turn on but you wont see anything. if the backlight is gone sometime with a flashlight you can see your windows screen. if the monitor works on another pc fine. then your pc is not booting. try clearing the cmos on the pc and check that the fans are moving...no video could be a a number of parts or issue. one could be the gpu went bad. if the mb has onboard video you can see if that port is working. the other issues would be bad power supply or bad motherboard.