PAL SNES RGB Cable Problem! HELP!

[Jackhead]

Hi mates,
I have an yellow touch in my RGB Signal from my PAL Multinorm SNES. I have pulled of the capacitors in the Cable. After that i place 75 ohm Resistors for it.
The Pic is sharpen but I have this :DOH: yellow Touch...
I have Test it with the Orginal GC RGB Cable and third.
I also test it without any capacitors. The SNES hangs on my Sony HDTV.
The Nintendo Chinch Cable works fine.
PLEASE HELP ME!
Here an Pic:

[link83]

Its usually suggested that you use 33ohm or 47ohm resistors in series on the RGB lines - not 75ohms.

You would only try to use 75ohm resistors if you were trying to 'replicate' what was used in the official PAL SNES Scart cable - which used a 75ohm resistor network to ground on the R, G, B and Composite lines.

I hope that helps :nod:

[c_rpg]

75 ohm resistors are used to set the impedance.

If you are getting a yellow touch it probably means you shortened the BLUE signal somewhere. Either that or your cable is messed up.
Try connecting each color one at a time and see where the problem lies.

[Jackhead]

thanks! I Test every wire for chancing color, but no chance.
So i will test the 33 ohm resistors tomorrow.
My Multimega with rgb Cable works fine.

[retro]

Use pots and adjust to suit, at least to test. I'd use 47 ohm resistors.

How is the SCART wired exactly?

This might be of use:

http://www.mmmonkey.co.uk/console/ni...l-snes-rgb.htm

[link83]

Use pots and adjust to suit, at least to test. I'd use 47 ohm resistors.

Its probably down to personal preference, but I have read in a few places that 33ohm resistors is also a good value to use.

RGB video signal levels should apparently be 0.7Vpp (Although I have also read 0.75Vpp is correct?) and it was worked out by Viletim over at the GamesX Forums that 47ohm resistors bring down the PAL SNES RGB level down to 0.69Vpp.

Nintendo's Official SNES PAL Scart cables apparently bring the RGB level down to 0.77Vpp.

The diagrams below by Viletim explain it better than I can. The thread they are taken from is here:-
http://nfggames.com/forum2/index.php?topic=3203.0

<EDIT> The diagrams are all messed up as apparently this forum wont allow you to leave blank spaces, but hopefully you get the idea!

Va = 1.4Vpp (measured)
Vb should be 0.7Vpp (video standard)

R1 is inside all PAL Super Nintendos
R3 is inside all SCART TVs

What Nintendo did:
Va--[R1]--+---------+--- Vb
30 | |
[R2] [R3]
|75 |75
+---------+--- Ground
Vb = 1.4 / (30 + 75//75) * 75//75 = 0.77Vpp

What I did:
Va--[R1]----[R2]----+--- Vb
30 47 |
[R3]
|75
+--- Ground
Vb = 1.4 / (30 + 47 + 75) * 75 = 0.69Vpp

So using Viletims diagrams shown above I worked out that 33ohm resistors would probably be a more appropriate value to match the 'official nintendo' RGB levels (Assuming you are not going to try and copy Nintendo's original cable design) as it will bring the RGB levels down to 0.76Vpp.
What im suggesting:-
Va--[R1]----[R2]----+--- Vb
30 33 |
[R3]
|75
+--- Ground
Vb = 1.4 / (30 + 33 + 75) * 75 = 0.76Vpp

...39ohm resistors would also probably be just as good, and would be a good 'compromise' between the two suggested levels.

I have personally tried all three recommended resistor values (33ohm, 39ohm, and 47ohm) and to be honest I couldnt see a huge visual difference between them.

At the end of the day its a small difference and its completely down to personal preference what you prefer :nod:

[Alchy]

The diagrams are all messed up as apparently this forum wont allow you to leave blank spaces

You can use code tags, like

[code]whatever[/code]

Decent info, anyway.

[link83]

You can use code tags, like

[code]whatever[/code]

Decent info, anyway.

Thanks - I just tried to edit my post and add the code tags but couldnt get it to work at all :shrug:

[Jackhead]

Use pots and adjust to suit, at least to test. I'd use 47 ohm resistors.

How is the SCART wired exactly?

This might be of use:

http://www.mmmonkey.co.uk/console/ni...l-snes-rgb.htm

Thanks! An Poti is an good tip i think!
My GC RGB and third Party Cable looks different from the Cabels on the mmmonkey Page.
I have 4 capacitors, and i dont have the bridge with the Resistor like you can see in the Pics from there.
But the Pins are correct for RGB 7/11/15 .
I will try to test with lower Resistors today and make you Pics from it.
Thank you all for trying to find an Solution!

[karsten]

my suggestion is to get a NTSC usa or jap machine and use a GC rgb cable...

[Jackhead]

I have test it with an US/NTSC SNES on my HDTV and it works very well!
Also i know that that the Pal one work on en non HDTV too.
So i wonder where the Problem with HDTV.
I mod my PAL SNES (Ceramic White) Many work stucks on it :noooo: .
So i search for an Solution... Of corse i can buy an JAP SFC and put it into Pal Case...

[drakon]

it looks identical to what happens when I disconnect the blue wire from my rgb.....thing. Did you use too strong of a resistor on the blue line?

[Jamtex]

Try sticking a 75 to 220ohm resister on the composite sync / composite video pin, I found on some TVs the Sync is too strong and causes the colours to mess up so the display looks yellowly. Apart from that make sure that the RGB lines are wired correctly (use a multimeter...).