New build with a GA-z170x-ultra gaming mobo. Plugged in the Psu. Flipped the switch. USB and Graphics card show power, no problems. The second I push the button to power on the mobo I hear crackling and see a bright arc in the upper left corner of the motherboard. Pulled the plug and saw underneath all the smoke a charred mark right next the the 4x4 pin CPU power connector. All the wiring looks good. Nothing touching the back side of the mobo. Fire occurred in area where nothing could touch since case panels were removed. Could my PSU have caused this or did I get a defective mobo? Could there be other damage? Don't know what to do.... plz help!!