GSM-noise "buzz" issue
joerg at openmoko.org
Fri Oct 31 21:26:25 CET 2008
Am Fr 31. Oktober 2008 schrieb Angus Ainslie:
> On Fri, Oct 31, 2008 at 1:45 PM, Joerg Reisenweber
<joerg at openmoko.org>wrote:
> > You HAVE to replace R4303 0R with a 2k2 !! (check R from mic housing
> > MIC4301:2
> > to GND! Has to be 2k2, will read 0R usually)
> > Otherwise this cap fix CAN NOT work. Refer to schematics, please.
> Your original instructions said R4403, they also said that R4403 wasn't on
> any schematic so I didn't try to look for it. Where should it be in the
> schematic ? I didn't mention it but I did do that part as well. Well almost,
> the closest value I had was 2k
> Should it be R4303 ?
Sorry for any faults or ambiguities! Once again:
change R4303 (oh-three) [0R, MIC4301:2 to GND] to 2k2
R4304 (oh-four) is not in the published schem [any more], it's obviously been
replaced in schematics by C4306 [NC, MIC4301:1 to GND]. However you may find
R4304 in component placement diagram (you won't find C4306 there!). It's the
two empty pads left side of the component array left to mic. Symmetric to
If you want to retrofit C4306 with a huge capacitor, you could use the empty
pads of R4304 to connect it. You also *have* to make the R4303 0->2k2 change,
otherwise mic signal is shorted by this capacitor and you won't see decent
signal on mixer input.
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