SNES RGB -> Panasonic Plasma TV

Started by suneloon, March 31, 2009, 02:35:29 AM

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I own a PAL SNES, and a Panasonic TH-42PX71EA television. The AV cable that came with the konsole, gives a blurry and "twidgy" picture. So I bought an RGB scart cable. The picture is much clearer and crisp, but now it becomes "pixelated", og griddy. It´s as though there are diagonal lines running both left to right, and right to left. This leaves me with a picture that looks like something from my old Comadore 64...
I´ve tried every setting on the tv.

Please help !!

Thank you.

- Sune ???


Well Sune, I think you may need to take some pictures of your screen, 'cause I'm having trouble with the terminology you're using.  Twidgy and griddy?  Cool, but confusing.  =D

If you're saying that the RGB cable makes the picture so clear you can see the pixels, well that's kind of the point.  If you have some other problem (diagonal lines?) I think you'll need to clarify a bit.


Perhaps what he is seeing is similar to a moiré pattern?


Is your Scart cable designed for the PAL SNES? I only ask as I have never come across a Nintendo Scart cable thats already made up correctly for the PAL SNES (With the exception of the Official French SNES Scart cable, but thats very rare to find outside of France)

The PAL SNES needs different components to the NTSC SNES, or even the PAL GameCube. Theres a chart on the Wiki here:-

Also, I would make sure you are using a well shielded Scart cable as 'lines on the screen' sounds alot like EMI/RFI interference.

I hope that helps  :)


I´ll post some pictures asap!

It does resemble a "moiré pattern"!

This is the describtion by the seller, on the cable I've bought:

"PAL SNES (Super Nintendo) RGB and AV Scart cable
Specifically made to carry RGB signals from PAL SNES (Super Nintendo) consoles to your TV, not suitable for other consoles.
RGB provides superior image quality over RF, AV and S-Video
Cable also carries standard composite AV, when connected to any type of Gamecube, N64, SNES, Super Famicom and AV Famicom. This is useful if you don't have an RGB compatible console or RGB compatible scart socket on your TV.
1.8 metres long
Stereo sound
Brand new item. "

So I'm not crazy for thinking it shold simply work (without any mods)...

The schematics posted in the previous post seem, at first glance, kinda confusing for a noob like me, but I'll study them some more asap.

Thank you for your replies! It´s awesome finding a webpage filled to the brim with fellow nerds! :D And even though I may only be a noob-nerd when it comes to elektronic stuff - I´m very eager to learn! (I bought a soldering iron yesterday..).

- Sune


Hi again

If anyone cares: I ended up bying an official Nintendo Gamecube cable. I removed the 4 capaciters (?), and the picture is crystal clear! Sometimes the picture will blink once when loading a new screen, but other times it will not. I´m thinking this has to doo with the console itself, and not the cable?


- Sune


Glad you got it sorted  :)

The PAL SNES actually needs 75ohm resistors to ground on the RGB and Composite lines, which could be the reason you are seeing 'blinking'. The PAL Gamecube cable already has one 75ohm resistor to ground on the Composite line (Its hidden in the MultiAV plug) so really all you need to do is add 75ohm resistors to ground on the Red, Green and Blue lines.

There were four capacitors in the PAL Gamecube cable as one is for Composite Video aswell as RGB  ;)

P.S. I dont know about anybody else, but I was just waiting to reply as I thought you were posting pictures of the effect you were describing so that we could better diagnose the problem  :D


Yea sorry about the missing pictures  :-[. There are only so much time in a day, and as I decided to go another way, I didn´t think it was worth posting pictures when it was no longer an issue for me. I should have replied before. Sry.

When i first modded the Gamecube cable. I replaced the 3 original capacitors for the video signal, with 47 ohm capacitors. That was when i first observed the "blinking". So i pulled all 4 capacitors out, and simply soldered the connections together. This seemed to help! The blinking didn´t occur right away.  But when I play the console for 30+ minutes, the blinking comes back.

- Sune


My RGB modded French N64 came in today with a RGB cable, which works fine on my Sony Bravia LCD. If I use this RGB cable with a SNES I get the grid/chickenwire effect.

I also tried to use my 47ohm modded Gamecube RGB cable on the SNES, and then I also get the grid/chickenwire phenomena (which I have only experienced with N64 s-video so far).

The s-video cable doesn't have this effect with my (PAL) SNES. Is this the cable, or is the problem in the Bravia tv?

The color code would make it 47 ohm resistors as well (guess that could be, since I don't see any difference with my own 47 ohm cable).
Would 75 ohm perhaps fix the grid/chickenwire issue? Or no resistors at all?
Is the RGB cable I got with my French RGB modded N64 an official PAL SNES RGB cable? (it's got an AV block and is fully pinned). I tried to open is, but I have never seen anything like it, it's got this glue/kit stuff all over the place   :o


For illustrative purposes, is this what you're talking about?
Long ago, I had a cheap PS2 S-Video cable that showed a checkerboard pattern across the screen, which cleared up when I got a somewhat expensive and overbuilt one (not a Monster cable but similar to it, I wanted a sure thing lol).  This isn't SCART cables like what you're talking about, but I figured if this looks similar enough we'll all be on the same page.


I think these are kinda what I mean:

Though I have the idea is much worse with me than these shots (these seem quite subtle). I once saw a very good screenshot of the phenomena here, but no clue where to find it back  ;)
I'll make some photos, sometime soon I hope.

Hmmmmz, tried to make some photos, but it's really hard to see it then. If anyone has some tips for that? (like, good game to show it with, or certain colour combinations...?)


I've had that S-Video checkerboard effect before. Its the cables. Apparently crosstalk in cheap cables ones causes it.


consider using aluminium foil ( proper aluminium, not silver colour ones) and wrap around the cable in order to sheild the cable from cross talk, copper tape is much better, but much more expensive

a few wraps and hey presto, decent shielded cables


The odd thing with me is, if I use the same s-video cable I've got the checkerboard effect with the N64, but not the SNES.
With the RGB cable it's the opposite, N64 looks fine but SNES has a checkerboard effect...

You've got a link to the aluminium foil you're referring to? (just wrap it on the outside of the cable??)

So is checkerboard the term to use for this, or chickenwire and grids are used as well? ;)
Any other terms?


i am not sure why you have this anomoly for the n64/snes on s video and rgb as i don't even use pal rgb via scart ( i have modified rgb pc engine and official super famicom rgb 21 pin plugged to xrgb 2 plus), have you considered trying these machines and cable on another tv?


also, do you have a bravia 2, or bravia 2 plus or bravia 3 sony tv, i believe that bravia 2 sony tv have issues with certain rgb connections, currently i am using kdl-40ex420 via xrgb 2 plus, no problems,


The Sony KDL-HX800 is a Bravia 3.
I must add to that, it doesn't have s-video, so I have to run that via my Yamaha RX-V1071 receiver. So that s-video doesn't look proper with the N64 might be because of the receiver. But like I said, s-video with the SNES works fine and my previous (HD ready) tv also didn't display N64 s-video properly.

Using the same RGB cable and SNES on my JVC AV-29FT1 50Hz CRT tv the image is fine.
Next to that I tested s-video as well and noticed a HUGE difference between PAL and NTSC s-video. s-video on the NTSC N64 looked incredible on the CRT tv, while PAL NTSC looked ok but was so much less colourful. Was there an explenation for that?

Found some threads concerning PAL N64 s-video