3870 cradle charge

I don't own a iPAQ 38xx but one of my fiends and work buddies did however get a 3870 after a small "incident" with his old 3600 iPAQ and his belt buckle (I won't mention the details here). He has written this article about how to modify your cradle to charge the iPAQ via the USB cable (without a power cable). A guy called Charlie Reverte, have written an article like this about the 36/3700 series cradles, so if you have one of these things and want to do this modification, check out this page.

Please also note that this page is about 450 KB, so if you are on a slow connection, please have a little patience while it loads.

Introduction:
This is a description on how to modify your cradle, enabling you to charge your IPAQ without use of a power supply. You do not have to have any degree in electronics to do this yourself. Anyone can do this. The descriptions are short, because you are not supposed to focus on the reading but on the actual work that needs to be done. The modification can be made in less than 15 minutes if you are a bit firm on the fingers. First timers must calculate approx. 30 minutes to do the job. I have done this modification myself twice, and it seems to be working as expected. I give no guarantee that it will work for you, but I do not see any reason why it should not, if you follow these instructions carefully.

Prerequisites needed:

iPAQ cradle for iPAQ 3870
Soldering equipment
Wire cutter
Approx. 4 cm of wire
T6 screwdriver

Terminology used:

Circuit board
Screws
Bottom of cradle
Body of cradle
Release button and rod
Expanders
Top of cradle

What to do step by step:

Step 1: Loosen the four screws that hold the bottom of the cradle together with the body.

Step 2: And take the two units apart.

Step 3: Gently loosen the USB/serial cable from the cradle.

Step 4: Gently loosen the power plug from the cradle.

Step 5: Using the screwdriver, gently loosen the release arm and rod.

Step 6: Remove the expanders and the top of the cradle from the body.

Step 7: Remove the circuit board from the top of the cradle.

Step 8: Your desk should be looking somewhat like this.

Step 9: Locate the marked area (red circle) on your circuit board. This is where you have to solder the wire to on the one side of the circuit.

Step 10: Prepare your wire by removing a little bit of the insulation at each end. Gently heat the un-insulated ends and apply a little bit of tin.

Step 11: Track the red wire (marked with blue on the previous picture) to the back side of the circuit board. (marked with red on this picture). This is your first spot the solder the wire to the circuit board. Gently heat the tin solder and attach the wire. Keep the wire still until the tin is hardened.

Step 12: Pull the wire around the circuit board using the same space as the USB cable (it should be able to fit in).

Step 13: Bend the end of the wire into a 90 degree angle to ease the attachment of the wire to the circuit board (see red marking). At the same time prepare the spot where you have to attach the wire to on the front of the circuit board. Gently heat the spot (marked with the blue circle) and apply a little bit of tin.

Step 14: Your wiring should look like this by now.

Step 15: Now all we have to do is to re-assembly the cradle.

Step 16: Attach the release button and rod into the body again. (gently pressing it into place, marked with a red circle). Now for the most tricky part of the process. Attach the spring between the body and the release button. (marked with a blue circle).

Step 17: Slide the circuit board back into body using the place holder (marked with two red circles).

Step 18: Place the cable and the power plug into their right spots again (hold the spring in its place by pressing the button).

Step 19: Attach the expanders at each side of the cradle.

Step 20: Now your cradle should look like this.

Step 21: Attach the top to the body.

Step 22: Before you attach the bottom, press the expanders down until they are in level with the top, and press the release button to verify that everything is in order.

Step 23: Now attach the bottom to the body again and fasten the screws again.

Step 24: Finally attach you cradle to the USB port on your computer (without attaching the power supply) and check that the iPAQ starts to charge. Some people warn that you should not use your power supply on a modified cradle. I have however tried this on my own cradle and there does not seem to be any problems in this, however I do not see why you should do this, and doing so is (like everything else in this article) on your OWN RISK.

Step 25: If your iPAQ does not charge, go back to step one and check that you have done every thing right. If it does, congratulations, you have just modified your cradle successfully .