What you will Need
- 4x 100 Ohm resistors
- Ribbon cable (like an old floppy drive or IDE cable)
- DB25 Male connector
- Solid Core wire
- Solder
- Soldering Iron
Step by Step Instructions
Click the image to enlarge
Image credit to Will iam
You will be soldering resistors to the JTAG port on your router's circuit board. The JTAG port is located directly below the wireless card on the circuit board, and I have highligted it on the image above with a red square.
The JTAG port in composed of solder pads where you can attach your wires. Pin 1 is highlighted by the square drawn around the solder pad. On the DB25 connector, Pin 1 also marked with a square, or by some sort of colored marking.
- Solder one end of the resistors to each of the pads indicated. For the ground pad, solder a piece of wire of the same length as a resistor.
- Solder the ribbon cable to the resistors.
- Solder the other end of the ribbon cable to the DB25 port as shown in the diagram.
- Double and triple check your wiring to make sure everything is right.
Some Tips for Soldering
Try to solder the wires closest to the capacitor first, this way, you get the hard to reach stuff done first. If you do it last, then you will have to solder in a very tight spot. Using a multimeter to test the connection is always a good idea as well. Test your whole cable for continuity (make sure you test before the resistors, because they will count as enough resistance to not be an open circuit for some multimeters). If you don't have a multimeter, just verify by eye that the connections look firm and that there is a layer of solder connecting every join.
Most people have found that soldering to one of the pins on the circuit board of the router, Pin 12 (see diagram), is very difficult. Keep trying, and you will eventually succeed, it just takes a lot more heat than the other pins. Some report more success by heating that solder pad from the back of the motherboard, not the top.
Note that the wire attached to pin 12 on the motherboard attaches to two pins on the parallel port connector, pin 20 and 25. You can solder this up any way you like, with a Y connection, or with a wire between pins 25 and 20, and one of those pins also connected to pin 12 on the motherboard. Some other tutorials mention that they used cables with every pin between 20 and 25 connected to pin 12. This probably also works, but is not necessary.
When you are done, you should have a cable with one end that looks something like this:
And the other end looking something like this:
