I finally figured it out why the common is not used. Its because the the two headphone speakers are wired in series. I've never seen a headphone socket wired like this before.
The orange and yellow wires connect to the headphones and I'm assuming that the blue is used as a sense wire to determine when the headphone jack is pushed in.
Thanks again MikeO for the links and the good advise. I've fitted the new socket and it is working fine.
The orange and yellow wires connect to the headphones and I'm assuming that the blue is used as a sense wire to determine when the headphone jack is pushed in.
Thanks again MikeO for the links and the good advise. I've fitted the new socket and it is working fine.