[EnterNow]

Originally Posted by soopx

the easiest way might be to get a known good cable and check pinouts, cable thickness and voltages to narrow down the problem.

Have you had a look at this for comparison?

For some unknown reason the RGB output circuits differs between the NTSC and PAL consoles. As a result the cables are different too

Source

[soopx]

Yep, that's what I used. The only difference is that my 5v is jumpered straight from the 12v via an unknown resistor.

I added the 75v resistors myself though