Why Create A Micro-USB Cable For DC Power Only?

On a shelf in the garage that adjoins my home office there is a set of shelves with a number of boxes of cables. There are cables of various sorts; BNC type video, RCA audio leads, XLR audio cables, IEC power cords, IEEE-1394, Ethernet, RS-232 serial, USB, mini-USB, micro-USB, etc. I try to not discard anything that might still be useful. Call it recycling if you like. Perhaps hoarding if you’re in a less gracious frame-of-mind.

Recently, I went to the shelf to fetch a micro-USB cable with which to remove some files from my Nexus 4 cell phone. I just grabbed one of the 20 cables in the box, using it to connect the Nexus 4 to my laptop. The Nexus immediately indicated it was charging, but the laptop completely failed to acknowledge the attached device.

I found that to be odd. At first I poked at the laptop a little, but eventually fetched another micro-USB cable from the collection. Using the second cable the laptop issued forth the usual tone, indicating that a new device was attached. Evidently the first cable had only two of the four wires connected, so it provides only power.

That got me to thinking…how much did some manufacturer save by including a cable that was not pin-to-pin connected on a USB-to-micro-USB cable? It had to be a trivial sum, hardly worth considering. It’s certainly not worth having to track a different SKU for the charging cable vs the fully-functional cable that might also be used with products requiring real USB connectivity.

With a true commodity item like this kind of USB cable such a short-sighted approach just seems dumb.