Nexus One Headset Controls: Issue, Solution and the Aftermath


I've been using the Nexus One Headset for quite some time now and never had any problems. However recently I found out that the Headset controls stopped responding but the headphones worked fine. My first assumption was that some application would have latched on to the control bits. So I decided to factory reset the phone, although the issue persisted.


The issue was with the hardware. I decided to connect my phone to one of the spare HTC Desire headset, it worked. So the fault was with the Headset.

After searching the web and tearing in the hardware I could finally solve the problem.

My Problem:
The Unshielded copper wire wound around within the cable had torn due to twisting and turning of the cable.
This is the common (GND) for the function keys and hence the controls didn’t work.

Verifying it:
Hold the Multimeter across the 4th Connector (Sleeve) and the 3rd Connector (counting from the tip). The Multimeter should read as shorted or Zero Ohms when you press the play button.

Some of the Resistance readings across 4th and 3rd connectors:
Buttons pressed
Resistance
(Ideal value)
Resistance
(Recurring stable value)
Play/Pause
0 Ω (short-circuit)
0 Ω (short-circuit)
Previous
220 Ω
221 Ω
Next
600 Ω
605 Ω

Solution:
I connected the torn wires again and the controls worked. But I had to replace the jack with a new one since the copper wire had torn very close to the plug.

Note:
The plug is TRRS (Tip-Ring-Ring-Sleeve) type 3.5mm. 

Headset affected:
HTC RC E150/E160

Similar Headsets are provided with:
Desire, Desire Z, Desire HD

Below are some the images and wiring diagrams that might help you. There are images of the headset controls dismantled just in case if you are interested.

Conclusion:
Handle your hardware with care :)

Images:












6 comments:

  1. Wow this helped alot. im trying to wire some play/pause next, previous buttons into a NES controller for an amp and needed some diagrams and resistor values and this was PERFECT!!!

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  2. Very nice explanation, just one detail, if the headphones still work and only the controls are failing means that the MIC wire is broken, as this is the same for the controls. If the GND would be broken, you would also have no audio. I have the same issue, same phone and the 4th contact is dead, while I get ok readings in the 3-2 and 3-1 contacts, unless you are reffering as GND the blue and red copper wire...

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  3. is this really working? thank you...

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  4. @Chaim: Nice observation, however the when GND is broken only controls don't work. Notice that the ground for speakers are (L- and R-) that are routed separately. So you still get audio.

    @Darel: Yes it works, Hence the post :)

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