Dark white color and blurry image in bigger TVs after composite mod

[Spectreman]

In 14" TVs looks almost fine. You can see a little grayish in the white parts, but ok.

Now I tested in a 29" and looks super bad. The white is very dark. In Pitfall, the colour around contamines the white text above. Again, this happen a little in 14", but in 29" TV is way worse. That 29" TV works ok with my Genesis in AV. Is also a little blurry, but not like with the Atari signal.

One other effect is that the some blue colors has become very shinning. In Kaystone Kapers the police color becomes diffuse when is in front of one of background blue squares (this don´t translate very well in photo). This happen in both TVs.

The guy who did the mod is good, but specialized in TVs, not videogames. One thing that was made is convert from Pal-M (Brazil) to NTSC. But any 90s brazilian TV supports NTSC. And all the caps were replaced.

Any hint about what would be? Thks.

 

 

[Spectreman]

Update: could be a weak signal from the mod that some TVs did not like. Running the AV cable into a VCR greatly improved the image quality.