SNES 2 Flicker free RGB?

Started by Konsolkongen, August 16, 2011, 06:15:00 AM

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Konsolkongen

Hi. A month ago I got myself an American SNES2 because I wanted a console that could do both JAP and US cartridges. A friend of mine has a late model 1 US SNES (the extremely ugly one). I borrowed his for a while and using my original Super Famicom RGB cable plugged into my XRGB-3 the picture was amazing. Much sharper than the first model SNES's I have tested on this setup.
So I wanted a console with the same RGB Encoder as his, but since you can't tell them apart without opening them up I decided for the Model 2 instead as I assumed it would have the same encoder.

I got it home, opened it up and soldered in some wires for the RGB mod needed on this model. I followed this guide:
http://gamesx.com/wiki/doku.php?id=av:snes2rgb

I installed 100ohm resistors on the RGB lines and the picture was very nice. In fact, that Mega Man X picture is one I took using my XRGB-3, it's hard do see anything wrong with it.

But the other day I was playing Zelda LttP, it's a game with fairly plain graphics and now I noticed that all the large single-colored areas (grass) was flickering a little bit. I tried other games and they all suffered from this problem (title screen on Wild Guns and so on).

I borrowed my friend SNES1 again and confirmed that this wasn't a problem on his, so obviously something needs to be added to this mod before it's perfect.

I tried doing this more complicated version of the mod:
http://www.gamesx.com/rgbadd/snes2rgb.htm
- But I couldn't find any 22pf's in town so I used 18pf's instead. But it didn't make a difference, only the picture was darker from using 130ohms on the RGB lines, so I changed those to 75ohms, now it's a little brighter than my initial mod, but the flickering colors is still there, no more no less. I doubt the 22pf's would make much difference here.

There is a SNES schematic here:
http://www.caitsith2.com/snes/snes%20schematic.rar
- But I'm not sure if it's for the newer or older model SNES. On page 4 we find the paths from the RGB encoder to the AV output but it doesn't really look anything like either mod described on GameSX.

Anyone has any ideas how I can get rid of this nasty color flickering? Sure it's not noticeable for the most part, but it still annoys me :)

I have tried a RGB cable without 220uF caps and I also tried using c.sync for sync rather than composite video. Didn't change anything.

l_oliveira

For once, you might not have problems with the video encoder, as obviously it's NOT used for RGB outputs.

The SNES2 uses a different chip which has CPU, PPU1 and PPU2 combined into an single 160 pins IC.

Also, there's at least two versions of the PPU1 IC for the old models with separated chips with slightly different palettes in them.

It's barely noticeable, but on very specific games you can see the difference.

Konsolkongen

You're right. But I'm getting the RGB signals from the encoder right? So you are saying that even though the encoder chip is the same on my friends model 1 and my model 2 there might be other differences beforehand?

Perhaps there is nothing we can do?

ApolloBoy

I modded my SNES mini for RGB a while back and I've never had the problems you've experienced, although I use a Sony PVM monitor for RGB as opposed to an X-RGB3. Try connecting the RGB lines from the encoder with just the 75 ohm resistors, which is what I did for my mod.

Konsolkongen

Alright maybe I'll try that. Although the flickering was there too when I only used 100ohms and nothing else. Maybe it's just the XRGB-3 being overly sensitive, wouldn't be the first time :)