I built a new pc and about ten hours after running fine i plugged a flask drive into the usb slot and the computer just turned off, everything is running correctly from what i can see inside, fans, hard drive, graphics card and power supply was tested to see if it was enough power, through all the tests I have only come to the conclusion that the Motherboard might be a dud because it was the only piece i was not able to test in my friends computer swapping parts though the lights are still turning on in the motherboard if that matters or not, not sure what to do as far as fixing the problem or why the computer would just suddenly turn off right when i put the flash drive in the usb any ideas what to do?