Luma connected to Composite Video on Snes s-video cable?

Ok so i bought some cheap SNES S-video cables and they produce crap image, colors are washed out and image is very grainy, it looks like shit.

I found out that these cables have the LUMA pin connected together with the Composite video out.
Sounds to me like these cables are rubbish but would this be supposed to work fine?

 

S video and composite are the same signals sent differently. S video has a Luma and Chroma line as well as 2 ground lines making up the 4 wires it normally has. Chroma is all the color date sent on one line and Luma is the brightness control on second line. Compsite has these sent on the same wire. Reason for the shitty image is due to the wrong signal going on the Luma line from composite. Shouldn't be there AFAIK. There should be a dedicated Luma line somewhere artound there it needs to go to. If not then I'm lost. Anyone else who knows more about the SNES care to confirm or correct my theory?

 

The snes av out pinout has Separate Luma and Composite lines, but this cable uses the Composite video instead of Luma out of the Snes.
Allows them to use one fewer wire in the cable as the same cable also has a composite connector. Cable works well as composite but not as S-video.

Edit: snes av pinout: http://www.gamesx.com/wiki/doku.php?id=av:nintendomultiav

 

Test the wires on the S video cable with a multimeter to see where they connect to on the port of the SNES. If they go to anywhere else but pins 5 through 8 then you have a problem and it needs to be rewired correctly.

 

I already knew where they were connected, Luma was connected on pin 9 ( COmposite ). I modified the connector (snes side ) and changed the metal pin inside the connector to Pin 7 instead and it fixed the S-video image. Obviously i cannot use Composite video anymore but i dont care.

I hereby conclude this thread by saying that these cables are rip offs and are truly made wrong. I was trying to avoid that and ordered from an American reseller listing them as (quality products ) instead of a Chinese one. See where that go me??

Here is where i got em from: http://www.ebay.ca/itm/Super-Ninten...t=Video_Games_Accessories&hash=item3a6209c398