This hack describes how to modify a Treo 600 USB docking station to charge the Treo while allowing the device to be hotsynched. This is not covered under any warranty, so don't bother bitching if you burn up your Treo, cause your PC to explode, cause your significant other to leave you, etc..


Parts Needed Voltmeter
Handspring Treo 600 USB docking station
Handspring Treo 600 power adapter
USB cable (A to B) that you are prepared to sacrifice.
Soldering Iron, Solder, Solder Sucker, Cutters, other tools as needed
Beer (Of course)

The Hack
1:Go ahead and dissect your docking station and break it down to the USB cable and the PCB that it connects to. You will find a PCB similar to this one:


2:In order to check that your USB port is going to be able to supply the voltage, you first need to check your voltage on your power supply. Plug in your power charger to the short power cord going off of the USB cable. Take your voltmeter and check the voltage at the PCB on the black and red wires, which should be GND(ground) and VDOCK(+5V) on the PCB. This should be between 4.8 and 5.8vDC. Anything less than 4.8 and more than 5.8 and that means that your Treo could be damaged if you proceed with the modification as it doesn't charge using the standard voltage. For a refrence, my Sprint powersupply for my treo says "4.9VDC" but I get 5.5 at the PCB.

3:Take the USB cable and chop off the end that looks like the picture below:


This should leave you with a red,black,white and green wire and a shield (maybe). The shield won't be used for this application. Strip back about 2 inches of the cable and you should find the same four wires, black, red, white and green. Bare about 1/8 of the wire on the red and black wires and CAREFULLY plug in your usb cable into your PC. WARNING DO NOT SHORT THE RED WIRE TO THE SHIELD OR TO ANY OTHER WIRE! PERMANANT DAMAGE WILL RESULT. Carefully use the voltmeter and check the voltage again. This voltage should be closer to +5vDC then the power supply.

4:This is the final test to ensure that your treo is compatible. Take the USB docking station cable and make sure that neither the USB port of the existing cable AND the power cord are both disconnected. There should not be anything connected to this cable. Take the PCB and push it into your Treo so that it sticks out like the picture below. Take the red wire and hold it to the "VDOCK" solder trace, then the black wire to the "GND" solder trace. Two things should happen, 1: the LED should light up and 2: the treo should beep/light up/whatever to indicate that it is charging.

5: For your refrence here's how mine is wired up:
WireTrace
WhiteUSB-
GreenUSB+
BlackGND
RedVDOCK


6: Desolder the wires from the original cable and resolder your hacked USB cable in its place. Make sure that none of the wires are touching. Test it by plugging the USB cable into the PC and then set your phone into the cradle. The light on the front of the docking station should light as well as your Treo should also indicate that it is charging. To check your USB connectivity, perform a hotsync and make sure you get a successful sync. reassembling the docking station and plugging the USB cable into the computer.


That's it! Go have fun.