On Thu, 30 Oct 2008 12:11:47 +0200, Joerg Reisenweber <[EMAIL PROTECTED]> wrote: > Am Mi 29. Oktober 2008 schrieb Ole Kliemann: >> Hi Joerg and others, >> >> I haven't followed the whole thread as I only understand 1%. So just one >> quick and dirty question: >> >> I have the two years EU warranty and am going to send my FR to my >> distributor anyway because GPS is not working with the internal antenna. >> (Independant of SD card.) >> >> So if I send it in, is there any fix that could be applied for the >> buzz? Or is it worth to wait, say another week, because there will be >> something then? > > Seems you always could "upgrade" to the 'botch' fix found in A7 (It > *should* > work, as our TPE engineers found it worth to implement in A7 ;-): > > replace R4403: 0R -> 2k2 > add C4306: NC -> 100uF (probably you won't find a 100uF to fit in anywhere, > so > a 47uF might kinda suffice. C4306 pads aren't existent in A5/A6, but you > can > use pads of NC R4304 which isn't mentioned in public schematics) > > > > A _yet_unapproved_(!) variant is to use a LM336-2.5 in place of the huge > capacitor, and to > change R4305: 2k2-> 860R (to make LM336 operate on >400uA, when setting > MICBIAS to VDD*0.9) > You also have to > replace R4403: 0R -> 2k2 > In theory this rework should yield even better stabilization of MICBIAS > voltage, the path where ripple caused by GSM RF is introduced to audio > path. > See all but first 6 pics at http://people.openmoko.org/joerg/buzzfix-lm336/ > (first 6 pics are a nasty approach to cut pin4 using some dremel-like mill. > > Those are not related to LM336 fix) > > > >> >> And - if you allow me to be off-topic - is there any improvement fix for >> the headphone jack? I mean this hipass-filtering issue making music >> sound quite tinny. > a) place some decent 100uF (or as high cap as feasible) parallel to C4110 > and > C4111. Make sure you don't create another contamination path for RF > creeping > inside big can - maybe use a ferrite ring to block RF next hole where you
> route some wires from those big caps inside can to C4110/11. > b) *short* C4110 / C4111, and insert the 100uF somewhere else in audiopath, > > b1)e.g. near R4405 / R4407 (you can even replace these R by 100uF > capacitors). > You should remove R4117 and R4117 then, and instead place these 1k from > JK4401:pin2 and pin3 (! for JACK_INSERT function) to GND > b2) or even place the 100uF outside FR in the housing of your hs-plug or > 2.5->3.5mm adapter > > HTH > cheers > jOERG > Hi, Given all the work that is being done on these issues, I do not doubt that a solution will be eventually found. I'm pretty patient, and I can wait till we get there. There remains a question that still deserves a firm and clear answer though. Will we be able to send our devices to the distributors or to some customer care center to get those fixes applied ? Do we have some form of warranty ? Cheers, -- Marc-Olivier Barre -- --- MarcO'Chapeau ---- - www.marcochapeau.org - _______________________________________________ hardware mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/hardware
