GSM-noise "buzz" issue

[Angus Ainslie]

>
> On Tuesday 26 August 2008 14:22:54 Joerg Reisenweber wrote:
> > We found it's pin4 of JK4401 and only this pin that causes GSM-EMI-noise
> > issue.
> > We placed a ferrite bead to this pin, and it stops noise. Alas this isn't
> a
> > viable rework, as it is extremely fragile and doesn't fit into case.
> > See
> > <
> http://people.openmoko.org/joerg/GSM_EMI_noise/noise_stopped_by_athena_rew
> >ork/>
> >
> > We tried to find another way to place a bead in this rail, first result
> > (without bead yet), see
> > <
> http://people.openmoko.org/joerg/GSM_EMI_noise/noise_stopped_by_cut_pin4/>
> > This rework at least stops noise and should fit into case. It breaks
> > function of headset mic and hold-button, but keeps function of
> headphones.
> > We try to find a way to restore function of mic and button, based on this
> > rework.
> >
> > I will keep you updated.
> > Please note all this IS NO RECOMMENDATION FOR A REWORK, and we can't
> answer
> > any questions yet beyond what I've reported above.
> >
> > cheers
> > jOERG
>
>
Hi,

Even thought this is not not a recommended rework I started on it. I
(wrongly) assumed by just removing the connector that it would fix the noise
issue. It doesn't.

I'm assuming that is because pin 3 and 5 need to be shorted. I've been
trying to find the pinout for JK4401 but no luck yet. Is it

                   1-3-5              5-3-1
plugin end ->             or
                   2-4-6              6-4-2


Does anyone have a pin-out ?


Angus
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