Every case is different, so the outcome may vary, but i would believe from the info i've received, that it's a dead board. Try unplugging everything that isn't essential to the board, as it might cause a short. Hard Drives, SSDs, fans, unecessary PSU connectors, Graphics cards and and all but one stick of RAM (remember, if you don't know EXACTLY where/what the failure is, everything is a suspect). If it doesn't boot up after that, try and clear CMOS. Since the PC refused to start after the incident, it might corrupted.