I have been repairing the jack for my pair of Sennheisers for Android (I have done 3 attempts so far) but I can't seem to make the volume controls work.
To clarify, after the repair, the sound is alright, the microphone also works but none of the buttons work.
I am not sure what I have done wrong. The soldered connections are all ok, at least it seems like they are ok.
There are 6 wires in total, 3 grounds and 1 for right sound, 1 for left and 1 for mic, something like this:
Then what I soldered the mic, right, left wires to the their corresponding positions, and then I soldered all 3 ground wires to the ground position (not sure if the grounding of all 3 ground wires together is correct), the positions look like this:
What have I done wrong?
Many thanks for your help,
As Chris pointed in one of the anwers, the reason why the buttons were not working was because android uses CTIA specification and I wired things based on OMTP - a comparison is shown below.
After a rewired things based on CTIA as below, everything worked as expected.
Edit 2: Marking this question as answered although there is still one minor problem with the stereo where the right audio sounds very "echo-y" and not normal - for another thread.