Introduction: Rewire Old Nokia Handsfree (WH-102 & WH-205) to Use It With Android Phones (OMTP to CTIA Rewiring)

Hi,

First i want to say sorry about my level of english.

So before a month ago i was bought an used Nexus 4 and was amased that the phones comes without headphones. After some research on the internet i found that i can use an old nokia handsfree after some basic rewiring.

I want to say they are two standard ot 3.5mm 4 pole jacks. One is called OMTP and the other that we need is CTIA. The only difference between this two standarts is that ground and mic pole are swaped.

Тhe tools that we need is:
1. Soldering iron

2. Soldering stand (optional)

3. Multimeter

4. Knife or some other slim tool

Step 1: Open the Handsfree

This type of handsfree is closed with clips and it is easy to open and close. I'm using a knife for this, but if you have better solution suggest it.

Here is the internal of handsfree.

We have 5 cables coming from 3.5mm jack.

I will describe their function

WH-102 (Black)

  1. White wire - Mic+
  2. Gold wire - Mic GND
  3. Green wire - Left Headphone +
  4. Red/Green wire - Headphones ground
  5. Red wire - Right Headphone +

WH-205 (White)

  1. White wire - Mic+
  2. Gold wire - Mic GND
  3. Green wire - Left Headphone +
  4. Blue - Left Headphone GND
  5. Red/Green wire - RightHeadphone GND
  6. Red wire - Right Headphone +

We have another 4 cables, that are for the headphones (WH-102 & WH-205).

  1. Green - LEFT +
  2. Red/Green and Gold - GND
  3. Red - RIGHT +

Step 2: Multimeter - What Goes Where ?

Use a multimeter to find witch cable to which pin is connected. I think there is no difference between all Nokia headsets, but this step is to verify the wiring.

Use а multimeter on circuit mode or resistance , attach first probe to jack (recommended is to use a crocodile) and with the second touch the cables soldering point on the board one by one, until you hear BEEP from multimeter or see 0 or something close to zero. Repeat this for every one of the jack pins.

Step 3: Rewire the Handsfree

So practically we need to swap the microphone (Mic+) and GND wire, but it is not that simple. Because they are five cables for four pins there is two cables for the ground (one for mic and one for phones). After swapping the Mic+ and GND wire ( White and Gold), it is need to cut second GND cable(for WH-102 Red/Green, for WH-205 Blue and Red/Blue), because it is on your new Mic+ pin on jack and it makes short circuit, and make bridge between Red/Green(for WH-102) Blue,Red/Blue (for WH-205) soldering point and White wire and you are done with rewiring.

Note: In my picture the bridge is made directly from ground coming from jack to ground of headphones, because it is a little bit hard to make that small bridge, without touching near soldering points. It is no matter how it is done (WH-102 only)

In final configuration (CTIA) the cable are:

WH-102

  1. White Cable - GND (both mic and phones)
  2. Gold Cable - Mic +
  3. Green Cable - Left Headphone +
  4. Red/Green Cable - CUT/NOT USED
  5. Red Cable - Right Headphone +

WH-205

  1. White wire - Mic+
  2. Gold wire - Mic GND
  3. Green wire - Left Headphone +
  4. Red/blue wire - CUT/NOT USED
  5. Blue - CUT/NOT USED
  6. Red wire - Right Headphone +

Sorry for the missing picture of ready to use WH-205, but i lost it.

Step 4: Close Hands Free and Enjoy

You are done. On my Nexus 4 i can use it with all normal functions. Mic is working, key is work perfectly, so you can move between your tracks on music player, answering calls etc.

Thanks for seeing my FIRST Instrctables and sorry again for my bad english. I hope you understand everything

Cheers!