Album: pictures:Computer Stuff:RAZR-Cable-2006-08-24

I have a solar power adapter for generically charging USB devices. It gives the "unauthorized charger" message on my Verizon V3M when I use it with a normal USB cable.

I ordered figures 1 and 3 from "USB 2.0 Cable Assemblies and Connectors" from this page in DigiKey's catalog to make the connector, and to figure out what was going on.

I tested the voltage and resistance between each set of pins. This diagram doesn't seem to be completely consistent with what I've seen. This is probably because I have the stock from-the-box wall charger and the person who posted that apparently had a car kit adapter.
  1. +5v
  2. shorted to 3.
  3. shorted to 2.
  4. 200 Kohm resistor -> GND
  5. GND
So, that's what I did. I got a plain, type-A USB cable cut the end off, and used its +5 and GND wires. I shorted pins 2 and 3, and I pulled a blue wire off pin number 4, put a 200K resistor on it, and connected that to ground. The RAZR now charges like normal!

For a little less work, you can get the entire cable end as part of a car charger here for $3. That's just about as cheap as I could order the parts for my above trick!

See below for a complete set of pictures.

Dave Hansen's photo album

Generated byAlbum created by photo album generator a MarginalHack written by David Ljung on Tue Aug 16 10:28:41 2011