No picture on S-video modded KV-9PT50 with MiSTer, Dreamcast & PS2 work great

[Fuzzy_Dunlop]

I recently s-video modded a KV-9PT50 by following stabarz's recent post over on Reddit.

Quick recap of that mod (see attached screenshot of PCB from his post):

• luma goes into the composite input
• chroma goes into the jungle (pin 5) with a 75R terminating resistor and through a .1uF cap

Both my Dreamcast and PS2 work and look great through s-video on the KV-9PT50.

I recently received Antonio Villena's S-Video Adapter for MiSTer however it does not work. When turning on the MiSTer the TV flashes, but then I get no video.

I was thinking it was the MiSTer adapter, however the adapter works great over S-video when connected to a larger Phillips CRT, and on an older Samsung LCD and in both cases the picture looks really good. The MiSTer adapter also works on the KV-9PT50 over composite when switched to that input (physical switch installed as part of the mod), it just doesn't look great with a lot of dot crawl.

I posted this on Reddit and someone speculated there could be a sync issue with the mod. Would anyone have any idea what is going on and how to fix this? Thanks.

[Segasonicfan]

I recently s-video modded a KV-9PT50 by following stabarz's recent post over on Reddit.

Quick recap of that mod (see attached screenshot of PCB from his post):

• luma goes into the composite input
• chroma goes into the jungle (pin 5) with a 75R terminating resistor and through a .1uF cap

Both my Dreamcast and PS2 work and look great through s-video on the KV-9PT50.

I recently received Antonio Villena's S-Video Adapter for MiSTer however it does not work. When turning on the MiSTer the TV flashes, but then I get no video.

I was thinking it was the MiSTer adapter, however the adapter works great over S-video when connected to a larger Phillips CRT, and on an older Samsung LCD and in both cases the picture looks really good. The MiSTer adapter also works on the KV-9PT50 over composite when switched to that input (physical switch installed as part of the mod), it just doesn't look great with a lot of dot crawl.

I posted this on Reddit and someone speculated there could be a sync issue with the mod. Would anyone have any idea what is going on and how to fix this? Thanks.

I developed this mod and shared it first here on GameSX in August, 2014.  It is in this same sub forum.

My documentation shows there is more needed for the Luma signal to work correctly.  The pic you attached doesnt appear to have info on your Y input.  How are you injecting it?

Also the CVBS issue you are most likely having is "cross color" i.e. "rainbow banding" - much more annoying and noticeable than dot crawl.  This occurs when color burst is out of phase with sync and is very difficult to correct.