I got this RGB cable from a friend of mine which he used for his SNES. He wasn't sure if he ever got it to work or not, but it doesn't work for me in any case.
The RGB cable has got 100uF capacitors and not all pins are connected (like with the standard SCART blocks you got with the SNES). I'll see if I can find the box of it, I should still have it. It was a beam-shaped black cardboard box with the letters RGB on it in colour with some yellow lines around it.
I don't get any picture nor any sound. Tried it on different SNES, N64 and GC consoles as well as different tv's, but nothing nada zip.
Is it a hopeless cause, or do you think it can be fixed?
Could be that it's a Japanese 21pin RGB cable and not a European SCART cable, check the pinouts against those at gamesx with a multimeter.
Then again as you even had a box you can assume it's a Japanse one if it has Japanese writing on it.
The box doesn't have Japanese writing on it. But I have a japanese N64 now, I could try it with that when I have time :)
In any case, I'll try to make some photos of the box and cable.
Mind you, not all pins are connected and I don't have a multimeter ;)
If all you want to do is test for circuit continuity, a multimeter is not strictly required. Old TTL electronics testers would have on hand something called a logic probe, which would simply show if you had voltage or ground on a particular contact. You can wire up a crude one with a couple of wires, a 9 volt battery and an LED/resistor pair. If the lights goes on, you know the wire goes all the way through.
-KKC, trying to have fun at work and failing miserably...