PAL GameCube RGB problem

[SolidSnake]

So me and a friend of mine bought a second hand Gamecube the other day. We hooked it up to my HDtv with a thirdparty RGB cable that came with the GC.
At first it looked just fine, but then we got to mention that the image was way to bright. Even when we turned down the brightness of the tv.
So we went to a local gamestore and bought an official GC cable. But when we hooked it to the tv, we got a strange buzzing noise from the tv and also the
signal looked like it was getting distorted.
We went back to the gamestore with the GC and the cable and hooked it up on one of the tv's they had, and there the GC gave a perfect image. They said
it probably got to do with signal interference from other electronics hooked to the tv. So we unpluged everything, and tried it again, but no luck.
Does anyone have an idea on how to fix this problem?

(Sorry for any spelling errors, English is not my native language)

[imparanoic]

sounds like your tv can handle rgb very well? what brand of tv do you have?

[SolidSnake]

I have an LG 32" HDtv

[imparanoic]

some korean tv are known ( even medium- high end ish tv) to be not so compatible with rgb

[SolidSnake]

So there isn't anything I can do about it?
What about the brightness from the thirdparty RGB? isn't there a mod that can turn it down?
I read about removing the resistor, or adding one?

[imparanoic]

try rgb to component converter or rgb to hdmi.

if your machine was modded a ntsc gv to rgb then the expensive xrgb would be the solution ( but xrgb can not accept pal signals, tried this on my ps1/ps2)

[SolidSnake]

A bit pricey solution, and not really sure if it makes the brightness go away..
So you dont know about adding or removing the capacitors or resistors?
That seems to be the problem with the brightness in my eyes.