Sega Genesis S-Video mod giving vertical lines

[cheaterdragon1]

I recently modded my Sega Genesis model 1 for S-Video. I've tested the system and the S-Video is a bit of a mess and gives vertical lines throughout the picture. Does anyone know a way of correcting it?

I followed this video and did everything step by step: http://www.youtube.com/watch?v=1ikWVFDUb80

I did have both of the grounds on S-video share a spot if that makes a difference.

[FABombjoy]

I recently modded my Sega Genesis model 1 for S-Video. I've tested the system and the S-Video is a bit of a mess and gives vertical lines throughout the picture. Does anyone know a way of correcting it?

I followed this video and did everything step by step: http://www.youtube.com/watch?v=1ikWVFDUb80

I did have both of the grounds on S-video share a spot if that makes a difference.
Assuming that that video gives a value of 75ohms for the chroma amp, I would increase the resistance. Better yet, use a 1k pot instead of a fixed resistor & dial it in until it looks right. The commonly used value of 75ohms produces vertical lines in most of the TVs that I've tried the circuit on.