LCM flicker

[joerg]

Am Mo  10. März 2008 schrieben Sie, Carsten Haitzler:
> On Sun, 9 Mar 2008 21:53:24 +0100 joerg <joerg.twinklephone at gmx.de> babbled:
> 
> > > I took an LCM to pieces and there is one chip in the whole thing.
> > We both know this means nothing nowadays ;-)
> > 
> > When i heard of red-only flicker (i own no NEO at all, so i'm sad i can't 
> > reproduce), i had another look to the c-ds, and i see (p.7) the Red4 and 
Red5 
> > data lines to be rerouted, by a strange redesign for GTA02 (probably to 
save 
> > an R-Array chip), through U6002 (LPF?!?), whereas same datalines go to 
> > R-array(! NO LPF) RP6005 in GTA01. Well i'm wondering... 
> 
> actually got blue flicker as well. interestingly if the signal to the actual
> lcd (so this is internal to the lcm now) has both red and blu of equal 
value,

Andy mentioned, there's a RC-LPF in PCLK in GTA02 (introduced with R5/R4 issue 
mentioned by me).
I think signals of RGB-bus and PCLK should be checked for correct timing with 
a multichannel-DSO. RC-LPF may introduce delay to PCLK which has different 
impact with changing pixel-frequency (portrait/landscape), thus sampling 
RGB-data out of time frame for steady signal. This way digital data 
becomes "analog".
There might be all kinds of crosstalk on the databus from glamo to LCM, 
introducing hum or any intermodulation on the data, so bits start wobbling 
when PCLK is out of time.

jOERG