snes to jamma video problem

[gojirien]

Hi everybody, I didn't find a presentation topic, so let me introduce me quickly  .

My name's Vincent, I'm french, and I found this forum looking for a solution for my project to put my pal snes in my new astro city arcade cabinet.

As I am a rookie, and as I managed to put my megadrive in my arcade cabinet, I did the same process with my snes : use a sync splitter lm1881 to have video on the arcade monitor, and soldering the different wires on the little male scart connector of the snes, on the console side. But it didn't work at all, I had an image very instable, going from the top to the bottom of the screen.

I tried few hours ago to solder the composite video directly on the jamma connector, without the lm1881. With this I have a perfect image with the game killer instinct, but during the fights the image is really deformed. I tried with super mario world, and I have only a good image with the screen "mario starts"  .

Please anybody could help?