I will replace an old power supply for the S3 (black and only 1 A), which obviously has serious design flaws in the original and after some use shines with loose contacts. Cause 2 are the same mistake: once the rickety, unstable Fderkontakte to the power supply pins (220), on the other hand the insufficient force against influences protected USB socket, tear off their lands sometime.
It is therefore in no way an indication of forgery when the black 1 A power adapter turn by loose connection! That's Samsung technology!
I hope in this sequel here you have learned.