Why doesn't any old microusb-usb cable work?

[theWUbear]

I have an old microUSB to USB cable from an LG decoy; obviously it plugs into the GSN and plugs into my comp's USB port, as I used to do with my Decoy to charge it. However, the GSN is not recognized. When I use the official plug I received it works. Just for the sake of my curiosity, anyone have the technical know how to explain how these cords can be different?

I used to things cables are cables...apparently not

 

[Slug]

Unmerged (moved) from charging-related thread.

theWUbear, the cable from the Decoy may not have all the pins required by the Nexus wired up. I've seen similar with an HTC Desire Z; a cable that is fine for charging but can't be used for transferring data as no device is detected.

 

[Graham84]

I noticed the same thing when I tried to use a couple older cables that work fine with my Droid X. They won't even work to just charge the phone. Kind of annoying...