Can anyone improve the rgb output on my duo?

[incrediblehark]

So I tried the cap swap and its very close, but not quite there yet. I attempted to take some pics and will upload them later

[thesteve]

ya could try adding a ceramic chip cap across the pins hu6260 pin43 to ground (pins 41 and 42) for additional filtering.
it was a major improvement right?

[incrediblehark]

It was only a marginal improvement, but still an improvement I believe. The jailbars are very close to being gone. Still gotta up the pics, hoping to get a chance tomorrow.

[ogre]

Holy crap does this actually work? 

[thesteve]

try it
im sure other caps failing would also cause picture noise, but that cap is just not big enough

[incrediblehark]

Ok, so here are pictures of the two systems. RGB Output is using the same cable, on the same display, a Sony PVM Monitor. Both were tested using PC Genjin 2.

Here is the PC Engine:




And this is the Turbo Duo:



As you can see there is hardly any difference, both systems have a great picture, but the Duo does have the more noticeable vertical lines. It probably sounds like I'm being extremely anal about this, its just that I would like to use the Duo as my everyday system but if the PC Engine has the better picture I'll just stick with that one.

[thesteve]

wow those are narrow lines.
my tests involved wider lines that were less distinct.
the pic looks a bit weak on the duo as well, that deserves investigation

[incrediblehark]

Thats what I meant when I was saying the picture was brighter on the pc engine. well the pics speak for themselves!

[thesteve]

i just did 2 RGB mods
1 my black duo
2 an IFU
screen shot
the amp
installed

[Bernie]

Nice job Steve!  Hopefully this is what Beemer does to mine. 

[incrediblehark]

Very nice! that's a pretty small amp too. so you're not getting any of the lines like mine? for me its most noticeable on solid colored backgrounds like blue or green.

[thesteve]

i get a small amount on black and blue, but nothing close to as bad as yours.
take a volt meter and compare the dc voltages on the inputs to the amp.
if your voltages are lower on the duo it could mean a bad input cap on the amp.

PS you have the same duo as me
if you havent had a full cap change its highly recommended and does improve performance.

[HercTNT]

Steve, that is outstanding picture quality on that. And i thought mine looked pretty good. I dont get any of the lines that incredibleshark has, but i do have some jailbars only when black is showing. those jailbars exist though all the time not matter what i'm doing. i think my lcd is just crap.  Will putting that 220uf cap on that you mentioned help regardless of what rgb mod you have?  I have 1 uf ceramic caps, you recommend putting them from pins 41,42, and 43 to ground?

[thesteve]

pins 41 and 42 are ground
so the cap from 42 to 43, and if you bridge 41 to 42 no prob
yes its an improvement to any (even composite)

[HercTNT]

the ceramic caps i have are not polarized so i would solder one leg on 42 and one on 43 and i would be good to go eh?  I know i'm just repeating what you just siad, but i'm being extra careful. you mention a 220uf cap on c961 as well. what exactly does that do?