So I whittled off all of the molded plastic and got down to the metal parts, then inside of that I chewed away more molding material to see that the unused pin didn't have any accessible solderable metal showing - it's a tiny plug! So I removed it (firm but gentile pulling) from the 5-pin plug and used a pin from my wife's sewing basket to replace it - by sticking it through the hole the original pin left and letting it stick out in back far enough to attach the resistor etc. Mine was an ugly project, though, since the unused pin was not connected to a wire in the USB cable I used.

Now, as your final photo shows, it does both. Normally when attached to a USB port the Zen charges but will not play ('docked' for file transfers), and just connecting the 2 power wires the Zen plays but does not charge (wtf?). Googled 'USB pinout' and I liked which shows that the resistor you specify is using an 'undefined' pin - which explains (for me) how the Zen detects it and knows what to do. Thanks, this provided missing info for me. Last note: test your charge circuit WITHOUT powering pins 2&3, before adding that 22k resistor circuit shown in the diagram above.most devices will charge with only pins 1 & 4 in the circuit.

I have blown up more than one motherboard circuit due to 'accidental' powering of the data circuits. I do not recommend powering against your data-pins.

Keep this in mind, that a computer does NOT output data or power to pins 2 & 3 for any device, once it is connected, or data is being transmitted however keeping it plugged in will charge it. I see this as highly unlikely, but not definitive. Then again, I am not familiar with many of these specific devices being 'charged', and so a trickle feed to the data ports may be required to cause the device to accept a charge. You are putting power into your data ports.where pin 1 and 4 are all you need to power. I have seen a lot of these 'homemade' charging schematics on the internet, and am at a complete loss as to why anyone is 'powering' the data +/- pins (pin 2 & 3). Well, shorting the 'green' wire on an ATX computer power supply causes the power-supply to turn on.

Homemade zen for 2k