Disconnect EVERYTHING and start basic trouble shooting. No front panel USB connected/FP audio, etc. and only on-board video and 1 stick of RAM and CD/DVD. If it POSTs, throw in HDD. If it POSTs, throw in the 2nd stick of RAM. If it POSTs again, add in the video card. If it POSTs...you get the idea! Next connect USB to motherboard headers. Minimizing the number of variables/parts is the key to hardware diagnosis!