Trying to get 15Khz to work on Sony CRT TV

[Jehuty]

Since i saw a X68000 running on an Sharp trisync Monitor i try to get the 15khz mode from games to work on my Sony KD29X2D CRT-TV without success.
I own a CZ-600 and a X68000 XVI. Tried severel scart cables and adapters. One Cable with H and V Sync tied together (from Retrocable Shop), another one with the passive sync combiner from Bobs RetroRGB site and a UMSA from Arcadeforge.
While the CZ-600 does a good Picture on all tested games the XVI has several problems.
Capcom Games like Final Fight, Street Fighter 2, Daimakaimura work and have a good quality. But Mahou Daisakusen has too much blue, Sega titles (Afterburner / Hang On / Alien Syndrome) and Overtake mess totally up.
Best results on XVI are with the cable that ties H/V together (but broke on a try my 74ALS05 conected to OSSC)

I also tried to downscale with a DIY GBS-C, but that thing doesn´t really sync. Extron VSC500 does onyl 480i on output.
I already did a recap on the video board, no success.

So does anyone have an idea why the Colors on my XVI are so messed up ?
What can i do to get a 240p picture on my TV. Or is it while the X68000 does 256P ?

One thing, the XVI via the scart cable hooked up on OSSC does the right colors.
So CZ-600 on TV works, but XVI with same cables on OSSC will also work but not on CRT.

Attached some pictures.

1. Mahou to Blue on XVI
2. Mahou on CZ600, same TV, same cable
3. Afterburner on XVI
4. Afterburner on CZ600, same TV, same cable

[spectreman]

This should solve your problem, the USB cable is for 5V power supply, to generate a mixed synchronized video signal, a normal smartphone power supply will be fine.
They ship internationally, send them an e-mail in English and they will respond.
The English-language site is still in preparation, so I recommend using your browser's automatic translator.

https://classicpc.org/rgb15ピン2段→rgb21ピンrgbケーブル-混合同期信号生成回路/