Just remove the 5 pin black component that you mentioned for a straight through cable. The other components are for 16:9/4:3 and composite/RGB automatic switching. The NTSC SNES needs caps to remove the DC offset in the RGB signal. Not sure why the PAL SNES doesn't need them though, maybe it doesn't have a DC offset to begin with.
Thanks for the confirmation. I just removed the component, the dark image is fixed, but now I have the checkerboard pattern issue
Not sure if is a problem with the cable itself or the missing caps. The same things does not happen with the GC cable.
My eight pin to female scart has a built in sync stripper, I thought this would always give me a clear image.
Alternatively if you don't want to desolder you can pull out the R,G,B and composite video pins from the blue connectors and connect them together with some left over legs from capacitors/resistors.
Thanks for the suggestion, but it's a lot easier just remove the component