Last night, I opened my case to check for a fan that wasn't spinning.. I realized that it was unplugged then I plugged it and ready to go but.. when I connected everything back together, my pc didn't powered up (seconds later I smelled like something had burnt).. after that I began to get worried about my PSU or even my motherboard had burnt, so I began to test everything... I removed the video cards, just left one. Tested and it powered up but there was no POST and even some fans were not running at all. The video card fan didn't powered up and the motherboard integrated LCD didn't post anything.. it seems that the motherboard is not sending the power to run the fans.