Just upgraded to Radeon 6870 FROZR III & Fractal 650W PSU. Cleaned CPU Hsink while at it. Mistakenly plugged CPU fan into OPT fan conn. Got error flash on screen. Checked MB diagram and corrected connection. PSU will not stay on. CR15 on MB stays lit. What is CR15 and is there a way to reset error? Fans work until shutdown.