[Stedy]

@Ferix,

I will dig out one of my A500's at the weekend and try a few experiments.
I will feed the video through a summing amplifier so that I can apply DC offsets and see what happens. Will also try varying levels on the TTL Csync signal.

As one of the TVs I tested was sensitive to the sync signal, it should provide a good test case.

Have you tried the AC coupling of the composite video output?

Also, on the CVBS output of the Amiga, add a potential divider using a 36 ohm and 39 ohm resistor. This will reduce the amplitude of the composite video to less than 1V. Some video decoders, like the ADV7180 or the SAA7118 can not cope with a video signal that is greater than 1V peak to peak.

With colour composite video, the chrominance adds 200mV on top of the peak white. On the A500 composite there is no chrominance information of course.

I really want to fix this, for my own satisfaction and to lay to rest the many issues experienced with RGB to SCART cables on modern TVs.

On you TV, does it have the option to use RGB SCART or CVBS SCART?
The Akura TV I tested had these modes + Y/C (S-Video) SCART options.

The weekend is nearly here.

Ian