So my first pc build was using an asrock x470 master ac sli. I had a used corsair 750watt psu used, but the thing is is that I tested it on an old system and it worked fine booted multiple times. I built my pc it booted, gamed, shutdown then didn't even post but the motherboard still lit up. Fans spun for a second then stopped then the lights on the mobo stayed on, I still have the psu, new mobo, new psu. Anyone have any ideas on what even happened?