I have just changed my power supply (old one definitely broken) and now no power to most of my system. CPU fan is turning but no output to monitor and system does not sound like it is booting up and I have checked that there is power from all of the power supply leads. No Num Lock or Caps Lock lights on keyboard and USB posts do not provide power either. There was no power to the entire system for approx 7 days. Any suggestions or help????