My gateway LX6810 desktop computer with vista OS, went to sleep mode and won’t wake up. I tried unplugged the power cord and after 10 minutes plugged it back in, the psu and cpu fans running,HDD and dvd drive spining,video card fan running, no power led come up, no POST(no beep no display). removed RAM, Video card, disconnect HDD and dvd power, even removed CMOS battery refreshed and put back. but no beep, no other signs of life. What has happened to my PC? I really appreciate any help.