very strange problem - slight electric shock from USB ports?

[GoldenX]

Recently a client called me, saying her notebook melted a USB keyboard connector. The battery had dried out, she plugged it and went elsewhere to do other things, when she returned the cord was laying on the table, burned...

 

[Vikramsingh]

@GoldenX, the voltage at usb is 5V and caters low current, if the usb plastic has melted then that means probably short ckt at the usb or cheap plastic of male usb. But short ckt is detected by the laptop and computer would shutdown and wouldn't start and if usb is repaired then Windows would ask for 16 digit code.