I bought a Gameboy Micro but the adapter's cord was cut in the middle. I soldered the the cable and it should works but when I tested it with multimeter it seem that I soldered the cables upside down: But there is only one red wire into the cord the other wire is like shielding. There is no way to make a mistake. I checked my other adapters and everything is as expect. I don't want to risk my Gameboy. Can anyone check it's adapter and tell me what is the polarity?