An interesting issue that I had to look at today – a burnt out SATA power connector. Some pictures:
My guess is that the SATA connector, where it plugs into the drive, had some sort of short between the pins on the drive’s socket. It must have pulled a lot of current to so completely melt the connector, and vapourise the 5V (supply rated for 30A) copper conductor. There was no obvious damage to the circuit board or drive, ruling out a failure on the board/drive causing a short.