I cut the head off a micro USB power supply thinking I could improvise a full micro USB cable. I found only Vcc and gnd wires. So, I decided to tear into the connector itself. Inside the connector was this USB to micro USB adapter. Seems like 5-to-4 wiring with one of the pins on the 5-pin side not connected to anything--how a micro USB to USB should be wired. I tested connectivity with a multimeter, but I can't get any solder to stick on the D+ and D- pins on the 4-pin side. What type of material is this?